Semiconductor manfacturing method and semiconductor manfacturing apparatus

ABSTRACT

Particles are prevented from clinging to the back of a wafer in the notch alignment of the wafer, and the problems encountered when a plurality of wafers were aligned all at once are solved. Three support poles  105  are erected on a turntable  103.  The substrate outer periphery  104   b  of wafers  104  is supported by the tapered portions of support pins  107  protruding from the support poles  105.  The turntable  103  is driven by a single motor  106,  and all of the wafers  104  are rotated at once. During rotation, the notches  104   a  of all the wafers  104  are detected by an optical sensor  116  provided to a sensor pole  117,  and the angular position thereof is stored. The wafers  104  are rotated on the basis of the angular position data, and notch alignment is performed successively, starting with the bottom wafer  104 . The wafers  104  that have undergone notch alignment are successively picked up by the pick-up support pins  111  of pick-up poles  110,  and are retracted from the support poles  105  that are rotating for notch alignment. Once all of the alignments have been completed, the retracted wafers  104  are returned to the support pins  107.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a semiconductor manufacturingmethod including a process for detecting the orientation flat or notchof a substrate and aligning it to a specified position, and to asemiconductor manufacturing apparatus equipped with a substratealignment apparatus.

[0003] 2. Description of the Related Art

[0004] An 8-inch cassette that carries wafers generally has an openconstruction (with a lid-less open cassette, the bottom part is alsoopen), so the notch alignment of the wafers can be performed from theopening in the bottom of the cassette by standing the cassette uprightso that the wafers are vertical. However, a wafer carrier called a FOUP(Front Opening Unified Pod), which is a 12-inch cassette, has a closedconstruction, so notch alignment always requires the wafers to be takenout of the FOUP. Because the wafers inside the FOUP are ordinarily in ahorizontal state, to align the notches in a vertical state, the FOUP hasto be stood up vertically or rotated 90°. Changing the attitude of theFOUP by standing it up vertically or rotating it 90° is extremelytroublesome, which is partially due to the large size of the carrier.Also, when 25 12-inch wafers are carried, the FOUP becomes quite heavy,making it difficult to rotate it by 90°. In view of this, a method inwhich the wafers are taken out of the FOUP while it is still horizontaland the notches of the wafers are aligned in a horizontal state isconsidered easier than when this is done vertically.

[0005] An example of a mechanism proposed in the past for positioningwafers in a horizontal state is Japanese Laid-Open Patent ApplicationH6-13450. With this mechanism, the wafer is placed on an eccentricitycorrection jig having a conical sloped surface, the eccentricity of thewafer is corrected, the eccentricity correction jig is lowered, thewafer is moved from the eccentricity correction jig to a rotating stageand secured thereto by suction, the eccentricity correction jig is thenfurther lowered and retracted, the wafer is rotated on the rotatingstage in this state, and the notch on the wafer is detected by anoptical sensor, allowing proper alignment to be achieved. After thisalignment, the wafer is collected by the reverse operation. As a result,the eccentricity of the wafer is corrected all at once, and the wafer ispositioned more accurately.

[0006] With the above alignment mechanism, however, because the back ofthe wafer is supported by vacuum suction during the detection of notchposition, the generation of particles is inevitable, the problem withwhich is that these particles cling to the back of the substrate.

[0007] Also, the above alignment mechanism is only intended for a singlewafer, and while it is effective in terms of achieving good alignmentaccuracy one wafer at a time and making the mechanism simpler, becauseonly one wafer can be detected, alignment is slow when a plurality ofwafers are positioned one at a time, creating a bottleneck in theprocess and resulting in poor throughput for the apparatus as a whole.

[0008] It is possible to provide a plurality of the above-mentionedalignment mechanisms in series in order to position a plurality ofwafers all at once, but this results in a bulky mechanism. Furthermore,if an attempt is made to position a plurality of substrates all at once,this requires a complicated operation in which the angular position ofpreviously positioned substrates is left alone while subsequentsubstrates are being positioned, among various other problems that areencountered, and solving these problems is extremely complicated interms of both the process and the mechanism.

SUMMARY OF THE INVENTION

[0009] It is an object of the present invention to solve the problemassociated with prior art whereby particles inevitably clung to the backside of the substrate because this side was supported, and to provide asemiconductor manufacturing method and semiconductor manufacturingapparatus with which it is possible to prevent particles from clingingto the back of the substrate during substrate alignment.

[0010] It is another object of the present invention to solve theproblem associated with prior art whereby substrates could only bepositioned one at a time, and to provide a semiconductor manufacturingmethod and semiconductor manufacturing apparatus with which it ispossible to position a plurality of substrates all at once.

[0011] It is another object of the present invention to provide asemiconductor manufacturing method and semiconductor manufacturingapparatus with which throughput can be enhanced by performing substratealignment during the idle time of the substrate transfer unit thattransfers the substrates to a processing chamber or processing jig.

[0012] It is another object of the present invention to provide asemiconductor manufacturing method and semiconductor manufacturingapparatus with which it is possible to solve with ease the troubleencountered when a plurality of substrates are positionedsimultaneously.

[0013] The invention of claim 1 is a semiconductor manufacturing methodincluding a step of detecting the position of the orientation flat ornotch of a substrate and aligning to a specific position, wherein asubstrate transfer unit that transfers substrates to a processingchamber or processing jig is used for the orientation flat or notchalignment of the substrates.

[0014] When a substrate transfer unit that transfers substrates to aprocessing chamber or processing jig is used for the orientation flat ornotch alignment, it is easier to place and remove the substrates withrespect to the substrate alignment apparatus that performs theorientation flat or notch alignment. Also, since there is no need for aseparate transfer unit to be readied, the apparatus is more compact andlower in cost.

[0015] The invention of claim 2 is the semiconductor manufacturingmethod according to claim 1, wherein the orientation flat or notchalignment of the substrates is performed in a transfer chamber in whichthe substrate transfer unit is installed.

[0016] Because the orientation flat or notch alignment is' performed ina transfer chamber, the substrate transfer unit can be utilized moreefficiently. Also, because the substrate alignment apparatus isinstalled in the empty space of the substrate transfer chamber, there isno need for a separate chamber or the like in which the substratealignment apparatus is installed to be readied, which allows theapparatus to be more compact and lower in cost.

[0017] The invention of claim 3 is a semiconductor manufacturing methodaccording to claim 1, wherein the substrates are removed from asubstrate carrier by the substrate transfer unit and put into asubstrate alignment apparatus that performs the orientation flat ornotch alignment of the substrates, and the substrates are taken out ofthe substrate alignment apparatus by the substrate transfer unit afterthe orientation flat or notch alignment of the substrates andtransferred to the processing chamber or processing jig.

[0018] When a substrate transfer unit that transfers the substrates to aprocessing chamber or processing jig is used, it is easier to place andremove the substrates with respect to the substrate alignment apparatusthat performs the orientation flat or notch alignment. Also, since thereis no need for a separate transfer unit to be readied, the apparatus ismore compact and lower in cost.

[0019] The invention of claim 4 is the semiconductor manufacturingmethod according to claim 1, wherein the orientation flat or notchalignment of the substrates is performed ahead of time by exchangingsubstrate carriers and repeating the following steps (a) to (d): (a) thesubstrates are removed from the substrate carrier by the substratetransfer unit and put into a substrate alignment apparatus that performsthe orientation flat or notch alignment of the substrates, andorientation flat or notch alignment of the substrates is performed, (b)the substrates that have undergone orientation flat or notch alignmentare taken out of the substrate alignment apparatus and returned to thesubstrate carrier by the substrate transfer unit, (c) repeating theabove steps (a) and (b) until the orientation flat or notch alignment isfinished for all of the substrates in the substrate carrier, and (d) thesubstrate carrier for which the orientation flat or notch alignment ofthe substrates has been finished is stored on a storage shelf.

[0020] If the orientation flat or notch alignment of substrates to beprocessed in the processing chamber the next and subsequent times isperformed as much as possible during the idle time of the substratetransfer unit that transfers the substrates to the processing chamber orprocessing jig, such as while a substrate is being processed in theprocessing chamber, then substrates that have already undergoneorientation flat or notch alignment can be transferred to the processingchamber directly from the substrate carrier, without having to undergoorientation flat or notch alignment again, so the substrates can betransferred more quickly and throughput is enhanced.

[0021] The invention of claim 5 is the semiconductor manufacturingmethod according to claim 4, including a step in which, if theorientation flat or notch alignment of the substrates in the substratecarrier has been performed ahead of time, this information is stored, adecision as to whether the substrates to be transferred have alreadyundergone orientation flat or notch alignment is made on the basis ofthis information, and if the substrates to be transferred have alreadyundergone orientation flat or notch alignment, then the substrates aretaken out of the substrate carrier by the substrate transfer unit andtransferred directly to the processing chamber or processing jig withoutfirst going through the substrate alignment apparatus.

[0022] If the orientation flat or notch alignment of a substrate to beprocessed has been performed ahead of time, then a transfer path isautomatically selected such that a substrate is transferred from thesubstrate carrier directly to the processing chamber or processing jig,without going through the substrate alignment apparatus, but if theorientation flat or notch alignment of a substrate to be processed hasnot been performed ahead of time, then a transfer path is automaticallyselected such that the substrate is transferred from the substratecarrier to the substrate alignment apparatus, and is only transferred tothe processing chamber or processing jig after orientation flat or notchalignment, so there is no need for the user to be aware of whether thesubstrate has already undergone orientation flat or notch alignment(that is, no need to go to the trouble of checking whether the substratehas already undergone orientation flat or notch alignment and selectingthe transfer path).

[0023] The invention of claim 6 is a semiconductor manufacturing methodincluding a step of detecting the position of the orientation flat ornotch of a substrate and aligning to a specific position, wherein theorientation flat or notch alignment of each substrate is performed byplacing the substrate horizontally and rotating it while the outerperiphery of the substrate is supported by a substrate supportcomponent.

[0024] Because the outer periphery of the substrate, rather than itsback, is supported during the orientation flat or notch alignment, noparticles cling to the back side of the substrate. Also, because theorientation flat or notch alignment can be performed horizontally, thereis no need for the complicated operation of changing the attitude of thesubstrate when the substrate is transferred horizontally, and thisfacilitates orientation flat or notch alignment. This is particularlyadvantageous if the substrate has a large diameter, because changing itsattitude would be more difficult.

[0025] The invention of claim 7 is the semiconductor manufacturingmethod according to claim 6, including a step in which the substrate istemporarily retracted from the substrate support component, and therelative positions of the substrate and the substrate support componentin the peripheral direction are shifted, after which the retractedsubstrate is once again supported by the substrate support component.

[0026] More specifically, when orientation flat or notch alignment isperformed for each substrate by rotating the substrate support componentaround the substrate center in a state in which the outer periphery ofone or a plurality of substrates is horizontally supported by thesubstrate support component, it is preferable if each substrate istemporarily retracted from the substrate support component by thesubstrate retraction mechanism, the substrate support component isrotated around the substrate center during this retraction and therelative position of the substrate support component is shifted withrespect to the peripheral direction of the substrate, and each retractedsubstrate is returned to and once again supported by the substratesupport component.

[0027] Problems with the relative positions of the substrate and thesubstrate support components sometimes occur, such as in the course ofaligning the orientation flats or notches of the substrates, or afterorientation flat or notch alignment. When this happens, the substratesare temporarily retracted from the various substrate support componentssupporting each substrate, and during this retraction, the substratesupport components are shifted in the peripheral direction of thesubstrates so as to shift the relative positions of the substratesupport component with respect to the substrates. Problems with thepositional relationship between the substrate and the substrate supportcomponent can be solved by moving the substrate support component whilethe substrate is retracted, so as to shift the position of the substratesupport component with respect to the substrate.

[0028] The substrate retraction mechanism that retracts the substratefrom the substrate support component may be, for example, a substratepick-up mechanism provided such that it can be raised and lowered andcomprising three pick-up poles having pick-up support pins for pickingup and supporting one or a plurality of substrates, and this mechanismmay be used to raise the substrate such that there is no interferencewith the substrate support component. During retraction, the angularposition in the peripheral direction of the substrate is maintained withthe substrate in the picked-up state, and after retraction, thesubstrate is directly lowered and transferred from the substrateretraction mechanism to the substrate support component.

[0029] The invention of claim 8 is the semiconductor manufacturingmethod according to claim 7, wherein, in the shifting of the relativepositions of the substrate and the substrate support component in theperipheral direction, the position of the substrate support component iscorrected so that the orientation flat or notch of the substrate willnot overlap with the substrate support component, and so that thesubstrate support component will not block the forward path of thesubstrate transfer unit as the substrate is taken out of the substratesupport component by the substrate transfer unit.

[0030] More specifically, in a semiconductor manufacturing methodincluding a step of aligning a substrate, the substrate is temporarilypicked up and retracted from the substrate support component withoutmoving the substrate from its position in the peripheral direction, andduring this retraction the substrate support component is rotated aroundthe substrate center and the position of the substrate support componentis corrected so that the substrate support component will not overlapwith the orientation flat or notch, or so that the substrate supportcomponent will not block the forward path of the substrate transfer unitas the substrate is removed from the substrate support component by thesubstrate transfer unit after substrate alignment.

[0031] If the orientation flat or notch of a substrate overlaps with thesubstrate support component that supports the substrate prior tosubstrate alignment (orientation flat or notch alignment), the forwardpath of the substrate transfer unit may be blocked by the substratesupport component as the substrate is being removed by the substratetransfer unit after substrate alignment. In such a case, the substrateis temporarily picked up and retracted from the substrate supportcomponent without moving the angular position of the substrate in theperipheral direction. In the case of an operation for eliminating theoverlap between the orientation flat or notch and the substrate supportcomponent, the angular position of the substrate in the peripheraldirection is maintained during the retraction of a substrate prior tonotch alignment as well. During retraction, the substrate supportcomponent is rotated around the substrate center and the position of thesubstrate support component is corrected so that the substrate supportcomponent will not overlap with the orientation flat or notch, or sothat the substrate support component will not block the forward path ofthe substrate transfer unit (the latter case is called return to pointof origin). The problems mentioned above can be solved by performingthis return to point of origin.

[0032] The invention of claim 9 is the semiconductor manufacturingmethod according to claim 8, wherein, if there is overlap between thesubstrate support component and the orientation flat or notch of thesubstrate while the substrate outer periphery is supported by thesubstrate support component, the substrate is temporarily retracted fromsaid substrate support component and the relative positions of thesubstrate and the substrate support component in the peripheraldirection are shifted, after which the substrate is once again supportedby the substrate support component, thereby avoiding the overlap.

[0033] More specifically, in a semiconductor manufacturing methodincluding a step of performing orientation flat or notch alignment foreach substrate by rotating the substrate support component around thesubstrate center in a state in which one or a plurality of substrateshave been placed horizontally by supporting the outer periphery of thesubstrates with the substrate support component, when the substrateouter periphery is supported by the substrate support component, andwhen the orientation flat or notch formed on the substrate outerperiphery overlaps with the substrate support component so that theorientation flat or notch cannot be detected, the substrates aretemporarily picked up and retracted from the substrate support componentby the pick-up mechanism, during which time the substrate supportcomponent is rotated a specific amount, after which the retractedsubstrates are returned to the substrate support component, therebyavoiding the above-mentioned interference between the orientation flator notch and the substrate support component.

[0034] When a substrate is placed on the substrate support component,the orientation flat or notch of the substrate may land on the substratesupport component because the orientation flat or notch position of thesubstrate cannot be specified. If the orientation flat or notch lands onthe substrate support component, the substrate support component may getin the way of the detection sensor and prevent the orientation flat ornotch from being detected. In view of this, to avoid overlap between thesubstrate support component and the orientation flat or notch, thesubstrate is first picked up and retracted by the pick-up mechanism, andthe substrate support component is rotated a specific amount during thisretraction, thereby shifting the substrate support component withrespect to the substrate and eliminating the above-mentioned overlap.

[0035] Because the substrate support component is thus shifted withrespect to the substrate while the substrate is being picked up andretracted, thereby eliminating overlaps between the substrate supportcomponent and the orientation flat or notch, the problem of being unableto detect the orientation flat or notch can be eliminated.

[0036] The invention of claim 10 is the semiconductor manufacturingmethod according to claim 8, wherein the substrate is temporarilyretracted from said substrate support component after the orientationflat or notch alignment of the substrate, and the substrate supportcomponent is set in a tolerance position that doesn't block the forwardpath of the substrate transfer unit, after which the substrate is onceagain supported by the substrate support component.

[0037] More specifically, in a semiconductor manufacturing methodincluding a step of removing the substrates from the substrate alignmentapparatus after one or a plurality of substrates have been put into thesubstrate alignment apparatus by the substrate transfer unit and thesubstrates have been positioned, the substrate support component that isprovided to the substrate alignment apparatus and supports the outerperiphery of the substrates is set in a tolerance position that doesn'tblock the forward path of the substrate transfer unit, the outerperiphery of the substrates that are put into the substrate alignmentapparatus is supported by the substrate support component of thesubstrate alignment apparatus, and the substrates supported by thesubstrate support component are rotated along with the substrate supportcomponent so that the orientation flats or notches of the substrates canbe detected.

[0038] It is preferable if the substrates are positioned on the basis ofthe detection results, and the positioned substrates are picked up andtemporarily retracted from the substrate support component by asubstrate pick-up mechanism provided to the substrate alignmentapparatus in a state in which the position of the positioned substratesis maintained, during which time the substrate support component isrotated in order to avoid interference between the substrate transferunit and the substrate support component, which resets the substratesupport component to a tolerance position that doesn't block the forwardpath of the substrate transfer unit (return to point of origin), and theretracted substrates are returned to the substrate support componentafter this resetting.

[0039] After the substrate support component has been rotated and theorientation flat or notch alignment of the substrate performed, thesubstrate support component may come to the substrate placement positionof the substrate alignment apparatus, where the forward motion of thesubstrate transfer unit would be impeded. If the substrate supportcomponent comes to this placement position, the substrate transfer unitwill interfere with the substrate support component and the substratecannot be removed. In view of this, in order to avoid the interferencebetween the substrate transfer unit and the substrate support component,all of the substrates are first picked up and retracted by the pick-upmechanism while their positioned state is maintained, and the substratesupport component is rotated by a specific amount during thisretraction, which resets the substrate support component to its originalposition and eliminates the above-mentioned interference.

[0040] While the substrates are being picked up and retracted, thesubstrate support component that had been shifted in the orientationflat or notch alignment process is reset to its original position, sothe problem of being unable to remove the substrate after orientationflat or notch alignment is avoided.

[0041] The invention of claim 11 is a semiconductor manufacturing methodincluding a step of detecting the position of the orientation flat ornotch of a substrate and aligning to a specific position, wherein, inthe orientation flat or notch alignment of a plurality of substrates,the plurality of substrates are stacked and supported by a substratesupport mechanism and rotated all together by the required angle, theorientation flats or notches of all of the substrates are detected by adetection sensor, and the detection information is stored, the substratesupport mechanism is rotated on the basis of the detection information,orientation flat or notch alignment is performed for one substrate at atime, each substrate that has undergone orientation flat or notchalignment is retracted from the substrate support mechanism one by onewhile the position of each substrate in the peripheral direction ismaintained, and after the orientation flat or notch alignment and theretraction are finished for all of the substrates, the retractedsubstrates are returned to the substrate support mechanism.

[0042] Here, the detection information is positional information aboutthe angle of shift from the reference angle position when theorientation flat or notch has been detected. If the orientation flats ornotches of all the substrates are detected and this detectioninformation is stored in the process of a plurality of substrates beingrotated all at once and passed through the detection sensor, then evenif the substrates are further rotated subsequently, the orientation flator notch position can be accurately remembered as long as the detectioninformation is corrected according to the amount of rotation.

[0043] The reason that the detection information needs to be correctedhere is as follows. For example, when there is overlap between thesubstrate support component and the orientation flat or notch of thesubstrates, all the substrates are temporarily retracted and thesubstrate support component is rotated by a specific amount in order toeliminate this overlap, but in this case even those substrates that havealready had their orientation flat or notch positions detected arerotated by this specific amount. Correction of the detection informationis therefore necessary.

[0044] Orientation flat or notch alignment is performed for onesubstrate at a time, and the substrates are retracted from the substratesupport mechanism while the position of the substrate in the peripheraldirection is maintained, and after the orientation flat or notchalignment is complete for all the substrates, the retracted substratesare returned to the substrate support mechanism, so even if thesubstrate support position of the substrate support mechanism ischanged, there will be no deviation in the aligned orientation flat ornotch positions, and the proper orientation flat or notch alignment-willstill be possible.

[0045] The invention of claim 12 is the semiconductor manufacturingmethod according to claim 11, including a step of rotating the pluralityof substrates all at once by a specified angle when the orientation flator notch position of the plurality of substrates cannot be detectedbecause the orientation flat or notch position is too far away from theplace where the detection sensor is installed, and the orientation flator notch position is brought closer to the place where the detectionsensor is installed, where the orientation flat or notch positions canbe detected, through this rotation by the required angle.

[0046] When the above-mentioned required angle is different from thespecified angle, and the substrates are rotated all at once by thespecified angle, it is only possible to detect the orientation flat ornotch position by first rotating the substrates by the specified angleand then rotating them by the required angle. If the orientation flat ornotch position is far away from the place where the detection sensor isinstalled, detection of the orientation flat or notch position can befacilitated by rotating the substrates by the specified angle all atonce so that the orientation flat or notch position moves closer to theplace where the position detection sensor is installed.

[0047] No position detection sensor is placed on the side of thesubstrate alignment apparatus where the substrates enter because itwould obstruct the forward motion of the substrate transfer unit.Therefore, if the orientation flat or notch position is on the entryside, the orientation flat or notch position ends up being far away fromthe place where the sensor is installed. Accordingly, the substratesmust be rotated so that the orientation flat or notch position isbrought closer to the place where the sensor is installed. A similaroperation is sometimes necessary even when the orientation flat or notchis not on the substrate entry side of the substrate alignment apparatus.

[0048] The invention of claim 13 is the semiconductor manufacturingmethod according to claim 11, wherein, when the orientation flats ornotches of the substrates cannot be detected even when the substratesupport mechanism is rotated by the required angle, the following steps(a) to (d) are performed so as to allow orientation flat or notchdetection: (a) the substrates are retracted from the substrate supportmechanism, (b) the substrate support mechanism is rotated by a specifiedangle, (c) the substrates are returned to the substrate supportmechanism, and (d) the substrate support mechanism is rotated by therequired angle and the orientation flat or notch position is detected.

[0049] More specifically, the following steps (a) to (d) are carried outwhen the orientation flats or notches of the substrates cannot bedetected by the position detection sensor in a non-contact detectionprocess. Once these steps have been carried out, the orientation flatsor notches will go from an undetectable region to a detectable region,and the notches can be detected.

[0050] (a) The substrates are all retracted from the substrate supportmechanism,

[0051] (b) the substrate support mechanism is rotated by a specificamount in order to shift the relative positions of the substrates andthe substrate support mechanism in the peripheral direction,

[0052] (c) the retracted substrates are returned to the substratesupport mechanism that has been rotated by the above-mentioned specificamount, and

[0053] (d) the substrates are rotated by the required amount and thepositions of the orientation flats or notches of the substrates thathave been returned to the substrate support mechanism are detected bythe sensor.

[0054] When the orientation flat or notch positions of the substratescannot be detected, it is preferable if the alignment of a plurality ofsubstrates is carried out one substrate at a time by rotating theplurality of substrates all at once on the basis of the detectioninformation, and every time alignment is completed, the substrate whosealignment is finished is retracted from the substrate support mechanismin order to preserve the alignment result, and once the alignment of allthe substrates is complete, the retracted substrates are returned andsupported by the substrate support mechanism.

[0055] The above-mentioned required angle is different from thespecified angle, with the relationship being (required angle)>(specifiedangle). Even if the orientation flat or notch positions cannot bedetected when the substrate support mechanism is rotated by the requiredangle, they will be detected if the peripheral direction position of thesubstrates is shifted by the specified angle with respect to thesubstrate support mechanism, and the detection of the orientation flator notch positions is thus possible.

[0056] The invention of claim 14 is the semiconductor manufacturingmethod according to claim 11, wherein, in the alignment of theorientation flats or notches of the substrates to a specific positionafter completion of the orientation flat or notch position detectionoperation for all of the substrates, if the orientation flat or notch ofthe substrate cannot be aligned to the specific position with a singlerotation because the orientation flat or notch position is too far awayfrom the specific position, the following steps are repeatedly performeduntil the orientation flat or notch of the substrate is aligned with thespecified position.

[0057] (a) The substrate support mechanism is rotated the requiredamount in the direction that is the shortest path from the orientationflat or notch position to the specified position,

[0058] (b) the substrates are retracted from the substrate supportmechanism,

[0059] (c) the substrate support mechanism is rotated the requiredamount in the opposite direction from that in (a), and

[0060] (d) the substrates are returned to the substrate supportmechanism.

[0061] If, after the orientation flat or notch positions have beendetected for all the substrates, the orientation flat or notch positionsare far away from the specified position in the alignment of theorientation flat or notch position to the specified position, then itmay be impossible to align the orientation flats or notches to thespecified position with a single rotation due to the limited range ofmotion of which the apparatus is capable. In a case such as this, theorientation flat or notch position can be moved to the specifiedposition by repeating the above steps (a) to

[0062] (d) and shifting the position a little at a time. The shortestpath from the notch position to the specified position is selected fromthe stored detection information.

[0063] The invention of claim 15 is the semiconductor manufacturingmethod according to claim 8, wherein orientation flat or notch alignmentis performed all at once for a plurality of substrates.

[0064] Because orientation flat or notch alignment is performed all atonce for a plurality of substrates, there is a marked increase inthroughput.

[0065] The invention of claim 16 is a semiconductor manufacturingapparatus equipped with a substrate alignment apparatus that performsorientation flat or notch alignment for one or a plurality of substratessupported horizontally, wherein the substrate alignment apparatuscomprises a substrate support mechanism that has a substrate supportcomponent which supports the outer periphery of the substrate and thatrotates the substrate support component around the substrate center soas to rotate the substrate, and a detection sensor that detects innon-contact fashion the orientation flat or notch of the substratesupported and rotated by the substrate support mechanism.

[0066] Because the substrates are supported around their outer peripheryrather than on their back side, the particles that are produced in thecourse of substrate support do not cling to the back side. There is nofriction between the detection sensor and the substrate when theorientation flat or notch is detected in non-contact fashion by thedetection sensor. Therefore, with the present invention, the clinging ofparticles to the back of the substrate can be effectively preventedbecause the orientation flat or notch is detected without contact withthe substrate, and the outer periphery of the substrate is supported.

[0067] The invention of claim 17 is the semiconductor manufacturingapparatus according to claim 16, wherein a supporting tapered portion isprovided to the support component, and the outer periphery of thesubstrate is supported by this supporting tapered portion.

[0068] Because the substrate is supported in linear or point contact bythe supporting tapered portion, less frictional force is produced thanwhen a substrate is supported in surface contact, and there is also areduction in the particle generation that accompanies orientation flator notch alignment, so the clinging of particles to the back of thesubstrate can be effectively prevented.

[0069] The invention of claim 18 is the semiconductor manufacturingapparatus according to claim 16, wherein the substrate support componentfurther has a tapered portion for correcting substrate eccentricity.

[0070] When the substrate is supported by a supporting tapered portionvia a tapered portion for correcting substrate eccentricity, because thesubstrate is in a horizontal state, the substrate is automaticallycentered by its own weight in the course of the orientation flat ornotch alignment.

[0071] The invention of claim 19 is the semiconductor manufacturingapparatus according to any of claim 16, having a substrate retractionmechanism for retracting the substrate from the substrate supportcomponent of the substrate support mechanism.

[0072] More specifically, in a semiconductor manufacturing apparatusequipped with a substrate alignment apparatus that performs orientationflat or notch alignment for one or a plurality of substrates supportedhorizontally, it is preferable for the substrate alignment apparatus tohave a substrate support mechanism that has a substrate supportcomponent having a tapered portion and supporting the outer periphery ofthe substrate with this tapered portion, with this substrate supportcomponent provided rotatably around the substrate center, and thatrotates the substrate supported by this substrate support component, adetection sensor that detects in non-contact fashion an orientation flator notch formed at the outer periphery of the substrate supported androtated by the substrate support mechanism, and a substrate retractionmechanism that has a substrate support component for supporting theouter periphery of the substrate, with which this substrate supportcomponent is supported at the substrate outer periphery and one or aplurality of the substrate are temporarily retracted from the substratesupport component of the substrate support mechanism.

[0073] Because this substrate retraction mechanism allows the substrateto be temporarily retracted from the substrate support component, itsolves the problem encountered with the positional relationship betweenthe substrate support component and the substrate.

[0074] The invention of claim 20 is the semiconductor manufacturingapparatus according to claim 19, comprising a control component forcontrolling the substrate support mechanism and the substrate retractionmechanism as in the following (a) to (c): (a) the rotation of thesubstrate support mechanism is controlled such that the orientationflats or notches of a plurality of substrates are detected and theorientation flats or notches of the substrates are aligned one by one,(b) the substrate retraction mechanism is controlled such that thesubstrates that have undergone orientation flat or notch alignment aresuccessively retracted from the substrate support mechanism one by one,and (c) the substrate retraction mechanism is controlled such that theplurality of retracted substrate are returned to the substrate supportmechanism after completion of the orientation flat or notch alignment ofall the substrates.

[0075] More specifically, in a semiconductor manufacturing apparatusequipped with a substrate alignment apparatus that performs orientationflat or notch alignment for a plurality of substrates supportedhorizontally, the substrate alignment apparatus is equipped with asubstrate support mechanism that supports a plurality of substrates in ahorizontally stacked state and rotates them all at once, a sensor thatdetects in non-contact fashion the orientation flats or notches of thevarious substrates rotated all together by the substrate supportmechanism, a substrate retraction mechanism that temporarily retractsthe substrates from the substrate support mechanism, and a controlcomponent that controls the substrate support mechanism and thesubstrate retraction mechanism.

[0076] It is preferable for this control component to:

[0077] (a) control the rotation of the substrate support mechanism iscontrolled in order to rotate a plurality of substrates all at once anddetect the orientation flats or notches of the various substrates, andto align the various substrates one by one on the basis of the detectionvalue for the orientation flat or notch of each substrate, and outputindividual alignment completion signals when the alignment of thevarious substrates is complete;

[0078] (b) control the substrate retraction mechanism in order for thesubstrates that have been aligned to be successively retracted from thesubstrate support mechanism one by one on the basis of the individualalignment completion signals, and

[0079] (c) control the substrate retraction mechanism in order for theplurality of retracted substrate to be returned to the substrate supportmechanism on the basis of all the alignment completion signals.

[0080] Controlling the substrate support mechanism and substrateretraction mechanism with the control component as above allowsorientation flat or notch alignment of a plurality of substrates to beperformed smoothly with a single rotary drive component.

[0081] The invention of claim 21 is the semiconductor manufacturingapparatus according to claim 16, wherein the substrate support mechanismcomprises a turntable, a plurality of support poles erected on theturntable, a substrate support component that is provided to eachsupport pole and supports the outer periphery of each of a plurality ofsubstrates, and a single rotary drive component that rotates theturntable.

[0082] More specifically, it is preferable for the substrate supportmechanism to comprise a turntable, a plurality of support poles that areerected on the turntable and support a plurality of substrates, aplurality of substrate support components that are provided at aspecific pitch in the axial direction of the various support poles, havetapered portions protruding in the inward radial direction of theturntable, and support the outer periphery of the substrates with thesetapered portions, and a single rotary drive component that rotates theturntable on which the support poles are erected, and rotates all atonce the plurality of substrates stacked and supported on the pluralityof substrate support components.

[0083] Because only one turntable and one rotary drive component forrotating it are needed, the construction can be simpler. It ispreferable for the substrate support components supporting thesubstrates to be constituted by three support pins having taperedportions that support the substrate outer periphery, but do not have tobe pins as long as the contact surface area is small.

[0084] The invention of claim 22 is the semiconductor manufacturingapparatus according to claim 19, wherein the substrate retractionmechanism comprises a base provided such that it can be raised orlowered, a lifting drive component for raising or lowering the base, aplurality of pick-up poles that are erected on the base and pick up aplurality of substrates one at a time from the substrate supportcomponent as the base is raised and lowered, and a substrate supportcomponent that is provided to each of the pick-up poles and supports theouter periphery of the substrate.

[0085] More specifically, it is preferable if the substrate retractionmechanism comprises a base provided such that it can be raised orlowered, a lifting drive component for raising or lowering the base, aplurality of pick-up poles that are erected on the base so as not tointerfere with the plurality of support poles and that temporarily pickup a plurality of substrates one at a time from the support poles as thebase is raised and lowered, and a plurality of substrate supportcomponents that are provided to the various pick-up poles at a specificpitch in the axial direction in order to pick up the plurality ofsubstrates successively, starting with the lowest one, and that havesubstrate support components that protrude in the inward radialdirection of the base and support the outer periphery of the substrates,pick up the substrates from the substrate support components of thesubstrate support mechanism when the substrate outer periphery issupported as the base is raised, and return the picked-up substrates asthe base is lowered.

[0086] The substrates can be retracted from the substrate supportmechanism with the position of the substrates in the peripheraldirection maintained, with a simple construction in which substratesupport components are merely attached to pick-up poles.

[0087] The invention of claim 23 is the semiconductor manufacturingapparatus according to claim 22, wherein the substrate support componenthas a turntable, a plurality of support poles erected on the turntable,a substrate support component that is provided to each support pole andsupports the outer periphery of each of a plurality of substrates, and asingle rotary drive component that rotates the turntable, wherein thepitch P1 of the substrate support components provided to the pick-uppoles and the pitch P2 of the substrate support components of thesupport poles satisfy the relationship P1<P2.

[0088] If the pitch P1 of the substrate support components and the pitchP2 of the substrate support components satisfy the relationship P1<P2,then the plurality of substrates supported by the substrate supportcomponents provided to the support poles can be successively picked up,starting from the lowest one, by the substrate support componentsprovided to the pick-up poles.

[0089] The invention of claim 24 is the semiconductor manufacturingapparatus according to claim 23, wherein when n number of substrates aresuccessively picked up one at a time by the pick-up poles, the pitch P1of the substrate support components provided to the pick-up poles andthe pitch P2 of the substrate support components of the support polessatisfy the relationship (n−1)P1>(n−2)P2.

[0090] If the above relationship is satisfied, then the plurality ofsubstrates supported by the substrate support components provided to thesupport poles can be successively picked up, starting from the lowestone, by the substrate support components provided to the pick-up poles.Also, when the support poles are rotated in a state in which thesubstrates have been picked up by the pick-up poles, there will be nointerference between the substrates and the substrate support componentsprovided to the support poles or the substrate support componentsprovided to the pick-up poles.

[0091] The invention of claim 25 is the semiconductor manufacturingapparatus according to claim 16, wherein the detection sensor isconstituted such that it moves forward in the inward radial direction ofthe substrate when detecting the orientation flat or notch, and movesbackward in the outward radial direction of the substrate when notdetecting.

[0092] More specifically, it is preferable if the sensor is constitutedsuch that it is provided so that it can move forward in the radialdirection of the stacked and supported substrates, moves forward in theinward radial direction of the substrates and detects the orientationflats or notches of the substrates during the detection of theorientation flats or notches formed on the outer periphery of thesubstrates, and retracts in the outward radial direction of thesubstrates when not detecting, so that interference with the substratesupport components is avoided.

[0093] The detection sensor moves forward in the inward radial directionof the substrates and detects the orientation flats or notches of thesubstrates during the detection of the orientation flats or notchesformed on the outer periphery of the substrates, and retracts in theoutward radial direction of the substrates when not detecting, so thatinterference with the substrate support components is avoided.

[0094] The invention of claim 26 is a semiconductor manufacturingapparatus equipped with an orientation flat or notch alignment apparatusthat performs orientation flat or notch alignment for a plurality ofsubstrates supported horizontally, wherein the substrate alignmentapparatus comprises a plurality of turntables provided in a stackedstate and sharing a common center of rotation, on each of which isplaced one substrate, a plurality of substrate support componentsprovided to the various turntables for supporting the outer periphery ofthe various substrates, a plurality of rotary drive components forindependently rotating each of the plurality of turntables, and adetection sensor for detecting the orientation flats or notches innon-contact fashion.

[0095] Because there are a plurality of turntables on each of which isplaced a single substrate, alignment can be carried out individually,facilitating control.

[0096] The invention of claim 27 is the semiconductor manufacturingapparatus according to claim 26, further comprising a substrateretraction mechanism for retracting the substrates from the substratesupport components.

[0097] More specifically, in a semiconductor manufacturing apparatusequipped with a substrate alignment apparatus that performs thealignment of a plurality of horizontally supported substrates, thesubstrate alignment apparatus comprises a plurality of turntablesprovided in a stacked state and sharing a common center of rotation, oneach of which is placed one substrate, a plurality of substrate supportcomponents attached to the various turntables and supporting the outerperiphery of the plurality of substrates placed on the variousturntables and having tapered portions formed at their supportcomponents, a plurality of drive components for independently rotatingeach of the plurality of turntables, a fixed sensor for detecting innon-contact fashion the orientation flats or notches formed at the outerperiphery of the substrates supported by the tapered portions of thesubstrate support components, and a substrate retraction mechanism.

[0098] Even if there are problems such as with the positionalrelationship between the substrates and the substrate supportcomponents, the inclusion of this substrate retraction mechanism allowsthese problems to be solved without canceling out the orientation flator notch alignment.

[0099] The invention of claim 28 is the semiconductor manufacturingapparatus according to claim 27, wherein the substrate retractionmechanism comprises a plurality of pick-up poles that are erected suchthat they can be raised or lowered, and a plurality of substrate supportcomponents that are provided to the each pick-up pole, support thesubstrate outer periphery and pick up the substrates from the substratesupport components when raised, and return the substrates that have beenpicked up to the substrate support components when lowered.

[0100] It is preferable if the above-mentioned substrate retractionmechanism has a base provided such that it can be raised or lowered, alifting drive component for raising or lowering the base, a plurality ofpick-up poles that are erected on the base and temporarily pick up aplurality of substrates from the substrate support components as thebase is raised and lowered, and a plurality of substrate supportcomponents that are provided at a specific pitch in the axial directionto various the pick-up poles in order to pick up a plurality ofsubstrates, pick up the substrates from the substrate support componentsof the turntables when the substrate outer periphery is supported as thebase is raised, and return the picked-up substrates to the substratesupport components as the base is lowered.

[0101] Even if there are problems such as with the positionalrelationship between the substrates and the substrate supportcomponents, the inclusion of this substrate retraction mechanism allowsthese problems to be solved without canceling out the orientation flator notch alignment.

[0102] The invention of claim 29 is the semiconductor manufacturingapparatus according to any of claim 26, wherein the detection sensor andthe substrate support components are in a positional relationship suchthat there is no contact when the substrates are rotated. If thedetection sensor and the substrate support components are in apositional relationship such that there is no contact, there will be norestriction on the rotation of the substrate retraction mechanism orturntables, allowing for free rotation, or the orientation flats ornotches can be easily detected regardless of where the orientation flator notch position is, and orientation flat or notch alignment can becarried out more smoothly.

[0103] The invention of claim 30 is the semiconductor manufacturingapparatus according to claim 29, wherein when the detection sensor is anoptical sensor, then the structure in which the detection sensor and thesubstrate support components are in a non-contact positionalrelationship is a structure comprising a turntable that is smaller indiameter than the substrates, a substrate support component protrudingin the outward radial direction from the turntable and forming a supportcomponent that supports the outer periphery of the substrate, and anoptical sensor that is outside the turntable in the radial direction andhas a light receiving component or light emitting component disposed onthe back side of the substrate outer periphery that protrudes out fromthe smaller-diameter turntable when the substrate is supported by thesubstrate support component, and a light emitting component or lightreceiving component disposed on the front side of the substrate outerperiphery opposite the light receiving component or light emittingcomponent.

[0104] When an attempt is made to detect the orientation flat or notchformed at the substrate outer periphery with an optical sensor, if thediameter of the substrate is the same as the diameter of the turntable,then the turntable will block the path of the light that has passedthrough the orientation flat or notch, so the orientation flat or notchcannot be detected. Consequently, the diameter of the turntable is madesmaller than the diameter of the substrate, so that the outer peripheryof the substrate placed on the turntable will stick out beyond theturntable in the outward radial direction. As a result, contact betweenthe optical sensor and the substrate support component during turntablerotation can be eliminated with a simple construction in which thesupport component that supports the outer periphery of the substratesticking out beyond the turntable is merely formed on the substratesupport component.

[0105] The invention of claim 31 is the semiconductor manufacturingapparatus according to any of claim 26, wherein a rotary drive componentfor rotating the turntable is not disposed beneath the turntable.

[0106] The rotary drive component is a pulse motor, for example. If therotary drive component and the turntable are linked by a belt pulley,for example, and the rotary drive component is disposed in parallel tothe side of the turntable, then the thickness of the turntable and thatof the substrate supported on the turntable will be absorbed within theheight of the rotary drive component, so the apparatus can be morecompact in the height direction than when the rotary drive component isdisposed in series beneath the turntable. Because the rotary drivecomponent is not placed beneath the turntable, the apparatus can beshorter in height and more compact.

[0107] The invention of claim 32 is the semiconductor manufacturingapparatus according to claim 31, wherein rotary drive components thatare adjacent in the vertical direction are disposed so as to havedifferent centers of rotation.

[0108] For rotary drive components that are adjacent in the verticaldirection, interference between the rotary drive components can beavoided by staggering the rotary drive components so that the centers ofrotation are different, so the spacing between turntables can be kept towithin the desired spacing, and the apparatus can be made even morecompact.

[0109] The invention of claim 33 is the semiconductor manufacturingapparatus according to any of claim 26, wherein the substrate supportcomponents are transparent. Transparent members are made up of membersthat are transparent to the light handled by the optical sensor.

[0110] Because the substrate support components are transparent, even ifthe orientation flats or notches land on the substrate supportcomponent, the light will not be blocked by the substrate supportcomponent, allowing the orientation flats or notches to be detected.Therefore, there is no need to shift the substrate support componentswith respect to the substrates should the orientation flats or notchesland on the substrate support components, and this facilitates operationof the apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

[0111]FIG. 1 is an oblique view of the substrate alignment apparatus ofthe semiconductor manufacturing apparatus pertaining to the firstembodiment;

[0112]FIG. 2 is a front view of the same in the first embodiment;

[0113]FIGS. 3A and 3b are front views of the main components in thefirst embodiment, with

[0114]FIG. 3A illustrating the support poles and

[0115]FIG. 3B the pick-up poles;

[0116]FIG. 4 is a front view of the main components in the firstembodiment, and illustrates the relationship between the pick-up polesand the wafers;

[0117]FIGS. 5A and 5B are diagrams of the relationship between thewafers and a sensor pole used for detecting notches in the firstembodiment, with

[0118]FIG. 5A illustrating a retracted state and

[0119]FIG. 5B a state in which the sensors have been moved toward thewafers;

[0120]FIGS. 6A and 6B are principle diagrams of the optical sensorpertaining to the first embodiment, with

[0121]FIG. 6A illustrating the positional relationship between the waferand the optical sensor and

[0122]FIG. 6B being a curve of the change in the amount of lightreceived by the light receiving elements;

[0123] FIGS. 7A and FIG. 7B consist of correlation diagrams of thesupport poles, pick-up poles, optical sensors, and wafers in the firstembodiment, with

[0124]FIG. 7A being a diagram of when the wafers are put in, and

[0125]FIG. 7B when the support poles have been rotated 180°;

[0126] FIGS. 8A,8B,8C and 8D consist of diagrams of the operation of thepick-up poles in the first embodiment, with

[0127]FIG. 8A being when the first wafer is aligned,

[0128]FIG. 8B when the first wafer that has been aligned is picked up,

[0129]FIG. 8C when the second wafer that has been aligned is picked up,and

[0130]FIG. 8D when the fifth wafer that has been aligned is picked up;

[0131]FIG. 9 is a block diagram of the control component that controlsthe mechanisms in the first embodiment;

[0132]FIG. 10A is diagram of the interference between the support polesand the pick-up poles, and

[0133]FIG. 10B is a diagram of the notch search regions of the wafer;

[0134]FIG. 11 is a flow chart illustrating the operation of the firstembodiment when the notch is within the specified angle θ range;

[0135]FIG. 12 is a flow chart illustrating the operation of the firstembodiment when the notch is not within the specified angle θ range;

[0136] FIGS. 13A,13B,13C and 13D are detailed diagrams of the individualprocessing step, where

[0137]FIG. 13A is step 207,

[0138]FIG. 13B is step 209,

[0139]FIG. 13C is step 212, and

[0140]FIG. 13D is step 218;

[0141]FIG. 14 is a diagram of how the notch positions are graduallyshifted in the operation of the first embodiment when the notch is notwithin the specified angle θ range;

[0142]FIG. 15 is an oblique view of the substrate alignment apparatus ofthe semiconductor manufacturing apparatus pertaining to the secondembodiment;

[0143]FIGS. 16A and 16B are cross sections illustrating the drive systemof the turntables in the second embodiment, with

[0144]FIG. 16A being an embodiment in which the motor is disposed on thewafer side, and

[0145]FIG. 16B a comparative example of a direct-linkage type in whichthe motor is disposed opposite the wafer surface;

[0146]FIG. 17 is a layout diagram illustrating the relationship betweenthe support pins and the optical sensors for detecting notches in thesecond embodiment;

[0147]FIG. 18 is a flow chart illustrating the operation in the secondembodiment;

[0148]FIGS. 19A and 19B consist of diagrams of the second embodimentillustrating a case in which the notch position overlaps a support pin,with

[0149]FIG. 19A being a plan view of the wafer and

[0150]FIG. 19B an enlarged view of (A);

[0151]FIGS. 20A and 20B consist of diagrams of the second embodimentillustrating interference between a tweezers and a support pin, with

[0152]FIG. 20A being when the support pin is located in the forward pathof the tweezers, and

[0153]FIG. 20B when the turntable has return to its point of origin andthe support pin is out of the forward path;

[0154]FIG. 21 is an oblique view of the substrate alignment apparatus ofthe semiconductor manufacturing apparatus pertaining to the thirdembodiment;

[0155]FIGS. 22A and 22B consist of diagrams of the motor interference inthe third embodiment, with

[0156]FIG. 22A being a plan view and

[0157]FIG. 22B a vertical cross section;

[0158]FIGS. 23A and 23B consist of diagrams of the substrate alignmentapparatus in the third embodiment, with

[0159]FIGS. 23A being a plan view and

[0160]FIG. 23B a vertical cross section;

[0161]FIG. 24 is a vertical cross section of the main components,illustrating the pick-up mechanism in the third embodiment;

[0162]FIGS. 25A and 25B consist of diagrams of the wafer being picked upin the third embodiment, with

[0163]FIG. 25A being before pick-up and

[0164]FIG. 25B after pick-up;

[0165]FIG. 26 is a diagram of the third embodiment illustrating thelocation where the turntable supports with respect to the support pin;

[0166]FIG. 27 is a flow chart illustrating the operation of avoidinginterference between a notch and a support pin in the third embodiment;

[0167]FIG. 28 is a flow chart illustrating the operation of avoidinginterference between a tweezers and a support pin in the thirdembodiment;

[0168]FIG. 29 is an oblique view of the main components in the thirdembodiment in which the support pin is made of a transparent member;

[0169]FIGS. 30A,30B and 30C consist of diagrams illustrating the layoutof the substrate alignment apparatus in the semiconductor manufacturingapparatus of this embodiment, with

[0170]FIG. 30A being a plan view, 30B a front view, and 30C an obliqueview of a FOUP;

[0171]FIG. 31 is an oblique view of a specific substrate alignmentapparatus of the semiconductor manufacturing apparatus of the firstembodiment in a working example;

[0172]FIG. 32 is a diagram illustrating interference between a pick-uppole and a tweezers in the working example; and

[0173]FIG. 33 is a diagram of the wafer strain in the working example.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0174] Embodiments of the present invention will now be described. Theembodiments deal with a large 12-inch wafer as the alignment substrate,but the present invention is not limited to a 12-inch size. Also, a casein which the alignment mark on the substrate is a notch will bedescribed, but this may be an orientation flat instead. Furthermore, thenumber of wafers whose notches are to be detected all at once is fivehere, but is not limited to five, and may even be one.

[0175]FIGS. 30A,30B and 30C illustrate a vertical CVD/diffusionapparatus that is an example of a semiconductor manufacturing apparatusin an embodiment. FIG. 30A is a plan view, FIG. 30B is a front view, andFIG. 30C is an oblique view of a FOUP (the substrate carrier). Alsoillustrated is a substrate alignment apparatus 100 provided to thisapparatus. The semiconductor manufacturing apparatus primarily consistsof a transfer chamber 251 into and out of which wafers are transferredin FOUP units, a transfer chamber 252 in which the wafers 104 areexchanged between the transfer chamber 251 and a processing chamber 253,and this processing chamber 253 in which the wafers 104 are subjected tofilm formation or other such processing. The substrate alignmentapparatus 100, which is capable of aligning a plurality of substratesall at once, is located in the transfer chamber 252 in the center.Although not shown in the figure, the transfer chamber 251 is equippedwith an I/O stage, a FOUP loader, and a FOUP rack (storage rack), and,as shown in the figure, is also equipped with a pod opener 255 thatopens and closes the lid 254 a of a FOUP 254. The design is such thatwhen the lid 254 a is opened to the FOUP 254, in which the wafers 104are placed horizontally, the 12-inch wafers 104 can be removedhorizontally from inside the FOUP 254.

[0176] The FOUP 254 holding the wafers 104 in a horizontal state istransferred from outside the apparatus into the transfer chamber 251,either manually or by a transfer apparatus. It goes along a specificpath and is brought to a position provided to the pod opener 255, wherethe lid 254 a is opened. The transfer chamber 252 is equipped with awafer transfer unit 256 capable of transferring a plurality of wafers104 all at once, and the substrate alignment apparatus 100 which alignsa plurality of wafers 104 all at once. A plurality of wafers 104 aremoved from the open lid 254 a of the FOUP 254 into the substratealignment apparatus 100 all at once by a tweezers 257 of the wafertransfer unit 256.

[0177] After substrate alignment, the wafers 104 removed from thesubstrate alignment apparatus 100 by the wafer transfer unit 256 aretransferred to a boat 263 in a boat pull-out position. The phrase “boatpull-out position” as used here refers to the position (unloadingposition) where the boat 263 is pulled out from a reaction tube 258, andwhere wafer charging and discharging is performed with respect to theboat 263. The boat 263 also serves as a processing jig. The boat 263loaded with the required number of wafers 104 is transferred into thereaction tube 258 at the top of the processing chamber 253. After this,film formation, diffusion, oxidation, or other such processing iscarried out in the reaction tube 258. Upon completion of this waferprocessing, the boat 263 is lowered and transferred out of the reactiontube 258, the wafers 104 in the boat 263 are transferred from theprocessing chamber 253 to the transfer chamber 251 by the reverseoperation from that described above (without going through the substratealignment apparatus 100, however), and are loaded into the FOUP 254 andtransferred out of the apparatus.

[0178] In FIGS. 30A,30B and 30C, 259 is a transfer elevator, 260 is atransfer unit arm, 261 is a boat elevator, and 262 is a boat arm.

[0179] With the semiconductor manufacturing apparatus in this embodimentof the present invention, as mentioned above, the substrate alignmentapparatus is equipped with the transfer chamber 252 in the center, andnotch alignment is performed using the wafer transfer unit 256. Morespecifically, as mentioned above, a plurality of wafers 104 are takenout of the FOUP 254 and put into the substrate alignment apparatus 100all at once by the wafer transfer unit 256, and after notch alignment,the wafers 104 that have been taken out of the substrate alignmentapparatus 100 by the wafer transfer unit 256 are transferred directly tothe boat 263. After the required number of wafers 104 have been loadedinto the boat 263, the wafer transfer unit 256 is in a free state. Thisstate continues not only during processing, but also until the processedwafers 104 are removed from the boat 263. During this time, the drivesystem for portions other than the reaction chamber, such as the wafertransfer unit 256, the substrate alignment apparatus 100, and the podopener 255, can be moved freely, so this idle time can be utilized toperform notch alignment.

[0180] More specifically, during this idle time (such as during filmformation), a FOUP 254 carrying wafers 104 that have yet to undergonotch alignment is brought from the storage rack (not shown) to aposition of the pod opener 255, and the lid 254 a is opened. A pluralityof wafers 104 are transferred all at once from the open lid 254 a of theFOUP 254 into the substrate alignment apparatus 100 by the tweezers 257of the wafer transfer unit 256. After notch alignment, the wafers 104that have undergone notch alignment are loaded by the wafer transferunit 256 from the substrate alignment apparatus 100 into the FOUP 254located at the pod opener 255. This procedure is then repeated untilnotch alignment has been completed for all of the wafers 104 in the FOUP254, at which point the lid 254 a of the FOUP 254 is closed, and theFOUP 254 carrying the notch-aligned wafers 104 is returned to thestorage rack (not shown). This operation is performed as much aspossible during the idle time of the wafer transfer unit 256. So doingmakes it possible for the notch-aligned wafers 104 to be transferredfrom the FOUP 254 to the boat 263 without going through the substratealignment apparatus 100.

[0181] When the notch alignment of the wafers 104 is performed ahead oftime as above, it is preferable for this information to be stored. Ifthis is done, then a decision as to whether the notch alignment ofwafers 104 to be transferred has already been performed can be made inthe transfer of the wafers 104 on the basis of the above-mentionedinformation, and if the wafers 104 have already undergone notchalignment, then the wafers 104 can be transferred directly from the FOUP254 to the boat 263 without first going through the substrate alignmentapparatus 100. Also, if the wafers 104 to be transferred have notalready undergone notch alignment, the wafers 104 are transferred asmentioned above from the FOUP 254 to the substrate alignment apparatus100, and then transferred to the boat 263 after notch alignment. Thus,in the transfer of the wafers 104, the appropriate wafer transfer pathis automatically selected on the basis of the above-mentionedinformation, so there is no need for the user to be aware of whether thewafers 104 have already undergone notch alignment, nor is there any needfor troublesome operations such as selecting the wafer transfer path tobe performed.

[0182] By thus utilizing the idle time of the wafer transfer unit 256 toperform the notch alignment of wafers 104 that have not yet beenprocessed, those wafers 104 that have already undergone notch alignmentcan be transferred directly to the boat without going through thesubstrate alignment apparatus, allowing the notch alignment step to beskipped and achieving a corresponding increase in throughput.

[0183] The substrate alignment apparatus 100 provided to the transferchamber 252 will now be described in detail.

[0184] First Embodiment (FIGS. 1 to 14A.14B.14C.14D and 14E)

[0185] This is an example of a substrate alignment apparatus thatdetects and aligns the notches of five horizontal wafers all at oncewith a single motor.

[0186]FIG. 1 is an oblique view of the substrate alignment apparatus,and FIG. 2 is a front view. The substrate alignment apparatus 100comprises a pedestal 101, an annular base 102 elevatably provided overthe pedestal 101, and a turntable 103 rotatably provided over thepedestal 101 and disposed above the annular base 102.

[0187] A plurality (five in the illustrated example) of wafers 104 aresupported horizontally and in a vertical stack with a specific spacingbetween them, with the substrate outer periphery 104 b supported frombelow by a plurality (three in the illustrated example) of support poles105 erected at specific angles around the outer periphery of theturntable 103.

[0188] The three support poles 105 are distributed in an approximatesemicircle around the periphery of the turntable 103, which isreversibly rotated by a motor 106 (serves as the rotary drivecomponent), and the direction in which these poles are erected isparallel to the rotational axis of the turntable 103. Support pins 107,which serve as the substrate support components that support thesubstrate outer periphery 104 b of the wafers 104 from below, areprovided at a specific pitch in the lengthwise direction to thesesupport poles 105 such that they project like arms in the inward radialdirection of the turntable 103. Therefore, the wafers 104 are rotated bythe turntable 103 while horizontally supported by the support poles 105.The turntable 103 is attached to the pedestal 101 via a support 108, andthe motor 106 that rotates the turntable 103 is provided inside thesupport 108. A plate 109 that covers the surface of the wafers 104 isprovided at the top of the three support poles 105 so that particleswill not cling to the surface of the wafers 104.

[0189] The substrate support mechanism of the present inventionprimarily comprises the above-mentioned turntable 103, support poles105, support pins 107, and motor 106 (just one).

[0190] The five wafers 104 are picked up from the substrate support pins107 by the raising of three elevatably (in the direction of arrow a)provided pick-up poles 110, starting with the first wafer 104 for whichnotch alignment is completed. After being picked up, the wafers 104 arereturned to the substrate support pins 107 by the lowering of thepick-up poles 110. Here, the base 102 supporting the pick-up poles 110will not rotate merely by the raising or lowering of the pick-up poles110, so the angular position of the wafers 104 in the peripheraldirection does not move (remains fixed).

[0191] Pick-up support pins 111, which serve as the substrate supportcomponents and pick-up the wafers 104, project like arms toward therotational center, supporting the outer periphery 104 b of the wafers104 at a specific pitch in the lengthwise direction. As shown in thefigures, these pickup support pins 111 are provided in a number (such asfive) corresponding to the number of wafers 104. The three pickup poles110 are laid out in intervals of about 120° around the periphery of thebase 102, which is raised and lowered by a slide mechanism 113 and amotor 112 attached to the pedestal 101, with the direction in which thepick-up poles 110 are erected being parallel to the rotational axis ofthe turntable 103.

[0192] This raising and lowering motion is carried out smoothly becauseof a guide 114 provided between the pedestal 101 and the base 102. Thepick-up poles 110 are provided such that they can move forward andbackward in the radial direction (the direction of arrow b) in an erectstate, moving backward and out of the way so as not to interfere withthe support poles 105 when the wafers 104 are rotated, and movingforward during pick-up so that the pickup support pins 111 reach thesubstrate outer periphery 104 b. Accordingly, the pick-up poles 110 areattached to corresponding air cylinders 115 fixed to the base 102.

[0193] The substrate retraction mechanism of the present inventionprimarily comprises the above-mentioned base 102, pick-up poles 110,pick-up support pins 111, air cylinders 115, and motor 112.

[0194] A sensor pole 117 having optical sensors 116 for detecting thenotches 104 a of the five wafers 104 supported on the substrate supportpins 107 is provided to the substrate alignment apparatus 100. Thesensor pole 117 is provided such that it can move backward and forwardby a specific stroke in the radial direction (the direction of arrow c),just like the pick-up poles 110. When the notches 104 a of the wafers104 are to be detected, the sensor pole 117 moves forward so the opticalsensors 116 can draw closer to the substrate outer periphery 104 bwithout touching, and when there is no detection, the sensor pole 117moves backward so as not to interfere with the support poles 105.

[0195] As to the dynamic relationship of the support poles 105, pick-uppoles 110, and sensor pole 117 here, the support poles 105 are rotatable(to the extent that there is no interference with the support poles 105when the pick-up poles 110 move backward), but do not move forward,backward, up, or down, whereas the pick-up poles 110 do not rotate, butdo move forward, backward, up, and down. Only backward and forwardmotion is permitted to the sensor pole 117.

[0196] As to the mutual positional relationship, the support poles 105and the pick-up poles 110 are disposed concentrically. The support poles105 are disposed at intervals of about 90°, 90°, and 180° around thecircle on the wafer outer periphery, whereas the pick-up poles 110 aredisposed at intervals of about 120° around a circle further to theoutside than the support poles 105. The wafers 104 enter and exitthrough the space between the two support poles 105 that are 180° apartand are closer to the viewer in the figure. The wide black arrow is thedirection of forward motion, and the opposite direction is the directionin which the wafers 104 are removed. The sensor pole 117 is disposed onthe exact opposite side from the above-mentioned entrance/exit of thewafers 104, with the rotational axis of the turntable 103 in between.The reason the sensor pole 117 is provided on the opposite side is toprevent it from getting in the way of entry and exit. The five wafers104 are put into and taken out of the substrate alignment apparatus 100by the wafer transfer unit 256 (FIGS. 30A,30B and 30C) in a horizontalstate.

[0197] As shown in FIG. 3A, the support components supporting the wafers104 of the five substrate support pins 107 protruding from the supportpoles 105 have first tapered portions 118 with a relatively large taperangle. Second tapered portions 99 with a smaller taper angle than thefirst tapered portions 118 are continuously formed at the lower part ofthe first tapered portions 118.

[0198] The support faces of the first tapered portions 118 have tapersurfaces with an angle of θ=60°, which are termed first taper surfaces.The support faces of the second tapered portions 99 have taper surfaceswith an angle of θ=6.6°, which are termed second taper surfaces. Thefirst taper surfaces are used to correct the eccentricity of the wafers104 by means of the latter's own weight. The second taper surfacessupport the outer periphery of the wafers 104. The wafers 104 are not insurface contact with the substrate support pins 107, and are instead inlinear or point contact, which prevents particles from clinging to thebacks of the wafers. The proper angle for the second taper surfaces is2° to 7°. In other words, the first tapered portions 118 of thesubstrate support pins 107 are eccentricity correcting tapered surfacesfor correcting the eccentricity of the wafers 104, while the secondtapered portions 99 are supporting tapered surfaces for supporting theouter periphery of the wafers 104. The taper angles given here aremerely examples, and any angle can be used as long as the eccentricityof the substrate can be corrected and its outer periphery supported. Asingle type of tapered portion may also be used if the eccentricitycorrection and outer periphery support of the substrate can beaccomplished at the same time.

[0199] As seen in FIG. 3B, a taper, albeit very slight, is also providedto the wafer bearing edge surfaces 119 supporting the wafers 104 on thepick-up support pins 111 of the pick-up poles 110. This tapering resultsin point contact, and prevents particles from clinging to the backs ofthe wafers as they are picked up. Just as with the second taperedportions 99 of the substrate support pins 107 in FIG. 3A, the properangle of the tapered surfaces is 2° to 7°.

[0200] There is no need for eccentricity correction at the pick-upsupport pins 111 of the pick-up poles 110 because the wafers 104 areplaced there after notch alignment (after eccentricity correction), andthese pins should be given a slight taper as mentioned above so as toreduce the contact surface area with the wafers in order to preventparticles from clinging to the backs of the wafers.

[0201]FIG. 4 illustrates the relationship between the pickup poles 110and the wafers 104. Illustrated is a state in which the air cylinders115 fixed to the base 102 have been actuated and the pick-up poles 110moved forward to the wafers 104 side. Because the pick-up poles 110 areraised by the raising of the base 102 via the slide mechanism 113 by themotor 112, the wafers 104 can be picked up vertically by the pick-upsupport pins 111.

[0202] Next, the optical sensors 116 will be described. FIGS. 5A and 5Bare diagrams of the relationship between the wafers 104 and the sensorpole 117 to which are attached light emitting elements 116 a and lightreceiving elements 116 b of the optical sensors 116. FIG. 5A shows thesensor pole 117 retracted, while FIG. 5B shows the sensor pole 117advanced in order to detect notch positions.

[0203] To detect the notches, an air cylinder 122 attached to a supportstand 121 fixed to the pedestal 101 is actuated, which moves the sensorpole 117 from its retracted position (FIG. 5A) in the direction of thearrow, and positions the optical sensors 116 over and under thesubstrate outer periphery 104 b of the wafers 104 (FIG. 5B). If thewafers 104 are rotated by a specific angle in this state, the substrateouter periphery 104 b of the wafers 104 will pass through the spaces 123between the light emitting elements 116 a and the light receivingelements 116 b, which permits the detection of whether notches arepresent or not. What angular position the notches are in can be detectedusing an angle signal from the position detecting encoder of the motor106. The notch angular positions of the wafers 104 are stored in amemory device (not shown). After detection of the notch angularpositions, but before the pick-up operation, the sensor pole 117 isretracted (FIG. 5A). The sensors and wafers will interfere with eachother if the wafers are still inserted into the sensors when they arepicked up, and this retraction is intended to avoid this interference.

[0204] The principle of notch detection with the optical sensors 116will now be described through reference to FIGS. 6A and 6B. FIG. 6A isan oblique view, and FIG. 6B is a curve of the change in the amount oflight received by the light receiving elements.

[0205] The optical sensors 116 consist of the light emitting elements116 a, comprising light emitting diodes or the like located above thesubstrate outer periphery 104 b, and light receiving elements 116 b,comprising a CCD camera or the like located below the substrate outerperiphery 104 b. Light 125 from the light emitting elements 116 a isreceived by the light receiving elements 116 b, and a change in theamount of this light is used to search for notches. When the wafers 104are rotated, the amount of light received at the light receivingelements 116 b changes as shown in FIG. 6B. When a notch 104 a comesaround, the light 125 from the light emitting element 116 a which up tothat point had been blocked by the substrate outer periphery 104 b nowpasses through the notch 104 a, so there is a sudden increase in theamount of light received. The peak indicating this sudden jump in theamount of light received corresponds to a notched portion. Notchalignment can be accomplished, for instance, by rotating the wafers 104,checking the distance from the starting point of the first rotation tothe notches 104 a and the amount of light received at the lightreceiving elements 116 b, and halting the rotation when the notchesarrive at the light receiving elements 116 b on the second andsubsequent rotations.

[0206] Next, the operation of the substrate alignment apparatusstructured as above will be described through reference to FIGS. 7A,7Band FIGS. 8A,8B,8C,8D. FIG. 7A and 7B consist of plan views illustratingthe behavior of the wafers 104 in the detection of the notches 104 a,and FIG. 8A,8B,8C and 8D consist of diagrams illustrating how the wafers104 that have undergone notch alignment (indicated by hatching) aresuccessively picked up when five wafers are subjected to notch alignmentall at once.

[0207]FIG. 7A shows the wafers being loaded. Five wafers are loaded allat once into the substrate alignment apparatus by the wafer transferunit 256 in the direction of arrow a, and the loaded wafers 104 aresupported by the substrate support pins 107 of the support poles 105.The sensor pole 117 is disposed to the rear of the support poles 105.The pick-up poles 110 are retracted away from the wafers 104.

[0208] We will assume at this point that the angular position in theperipheral direction of the five notches 104 a supported by thesubstrate support pins 107 is Within a range of angle θ flanking anextension line AO of the line connecting the position B of the opticalsensors 116 and the rotational center O. A premise with this apparatusis that the notches 104 a are within a range of θ=60° (±30°). This isbecause the wafers 104 handled by this apparatus have already gonethrough a washing step, and while the notches 104 a may shift somewhatduring washing, the positions of the notches 104 a will never becompletely random among the five wafers 104, and this shifting isgenerally considered to be ±30°, so the movable range of this apparatuswas set at 60° (±30°) so as to cover this shifting. The movable range ofthis apparatus was set to a relatively narrow range here according tothe shifting of the notches 104 a in the washing step, but how much theapparatus can actually move is the range in which the support poles 105and the sensor pole 117 will not interfere with each other during notchdetection, and the range in which the support poles 105 and the pick-uppoles 110 will not interfere with each other during notch alignment,which are determined by the shape, size, width positioning, and so forthof the support poles 105, pick-up poles 110, and sensor pole 117.

[0209] When the turntable 103 is rotated by the motor 106 and thesupport poles 105 are moved from the state of the starting pointposition in FIG. 7A, the five wafers are rotated 180° counterclockwiseas indicated by the arrow, resulting in the state shown in FIG. 7B,which is the notch detection commencement position. The rotation may bein either direction, so the wafers may be rotated clockwise instead. Inshort, it should be possible for the optical sensors 116 to detect thenotches. As a result, the support poles 105 arrive at the position shownin FIG. 7B, and the notches 104 a approach the optical sensors 116.Because the pick-up poles 110 are fixed in their motion in theperipheral direction, there is no change in the angular position. Nor istheir any change in the angular position of the optical sensors 116 inthe peripheral direction. When the optical sensors 116 are moved towardthe wafers 104 in this state, the optical sensors 116 go from the dottedline position to the solid line position. At this point the motor 106 isrotated, the angular positions of the notches 104 a of the wafers 104are checked all at once, and the resulting information about angularposition is stored in a memory device. The angular position can bedetected using an angle signal from the position detecting encoder ofthe motor 106.

[0210] The operation of successively aligning the notches 104 a of thewafers 104 with the line OB on the basis of the above-mentioned angularposition data will now be described. The discussion here will be focuson aligning the notches 104 a with the line OB, but the notches 104 acan instead be aligned with any other position desired.

[0211] If the notch 104 a of the first wafer 104 is to the left of theoptical sensor 116, as seen in FIG. 7B, then the wafers 104 are rotatedclockwise on the basis of this angular position data to align the notch104 a at the position of the line OB, and the rotation of the motor 106is then halted. This completes the first notch alignment. FIG. 8Aillustrates a state in which the notch in the lowest wafer 104(indicating by hatching) of the five wafers 104 has been aligned withthe line OB, after which the pick-up poles 110 are moved in the inwardradial direction of the wafers, and the pick-up support pins 111 areslid under the outer periphery 104 b of the wafers 104. As shown in FIG.8B, the pick-up support pins 111 are raised by the slide mechanism 113so that the first wafer 104 that has undergone notch alignment is pickedup and moved away from the substrate support pins 107 of the supportpoles 105.

[0212] Next, in a state in which the first wafer 104 from the bottom hasbeen picked up, the support poles 105 are rotated and the notch 104 a ofthe second wafer 104 from the bottom is aligned with the line OB on thebasis of the detected angular position data. Once the second notchalignment is complete, the second wafer 104 is picked up by the pick-upsupport pins 111 as shown in FIG. 8C. Similarly, notch alignment and thepicking up of the wafers is repeated in order for the third, fourth, andfifth wafers. FIG. 8D shows a state in which the last wafer 104 has beenpicked up by the pick-up support pins 111 of the pick-up poles 110. Inthis manner all of the wafers 104 are transferred from the substratesupport pins 107 to the pick-up support pins 111. At the point when theabove operation is complete, the notches 104 a of all the wafers 104 areon the line OB.

[0213] When the first wafer is to be aligned, the pick-up poles 110 areretracted so the support poles 105 are able to rotate freely withoutinferring with the pick-up poles 110. However, after the pick-up poles110 are set in the position where the wafers can be picked up, thewafers 104 are limited to a rotational range (θ) such that there is nointerference between the support poles 105 and the pick-up poles 110 inorder that the picked-up state will be maintained and the notchalignment of the next wafer 104 can be performed. This range, however,must be at least large enough to cover ±30°, since that is how much thenotches may shift in the washing process. As to the timing at which thepick-up poles 110 are set in the position where the wafers can be pickedup, it may be after the notch position has been detected but before thenotch alignment is performed for the first wafer.

[0214] As discussed above, to pick up the wafers 104 one at a time afterthey have undergone notch alignment, the pitch P₁ of the pick-up supportpins 111 of the pick-up poles 110 and the pitch P₂ of the substratesupport pins 107 of the support poles 105 must at least be in thefollowing relationships in FIGS. 8A,8B,8C and 8D.

P₁<P₂  (1)

4P₁>3P₂  (2)

[0215] Formula 2 here holds true when the notch alignment is performedfor five wafers. When the notch alignment is performed for n number ofwafers, Formula 2 is as follows.

(n−1)P ₁>(n−2)P ₂  (3)

[0216] Actually, when P₁ and P₂ are determined, wafer bending and thespacing between the wafers 104 and the substrate support pins 107 andpick-up support pins 111 must also be taken into account. For instance,if the wafer bending is 0.3, then when the spacing ΔL between thesubstrate support pins 107 and substrate support pins 107 at the lowestlevel shown in FIG. 8A is equal to 2 mm, P₁=19 mm, P₂=23 mm, and thepick-up pitch=4 mm. This will be described in detail in the examplesgiven below.

[0217] Upon completion of the above series of operations, the threesupport poles 105 are away from the position shown in FIG. 7B because ofthe repeated notch alignment operations. Thus, the turntable 103 isrotated here to return the support poles 105 to the positions they havein FIG. 7B. Next, the pick-up poles 110 are lowered, and all five of thewafers 104 are returned to the substrate support pins 107 of the supportpoles 105 from the pick-up support pins 111. After this return, thepick-up poles 110 are retracted to the outside of the wafers 104. If thesupport poles 105 are rotated 180° in this state, they return to theiroriginal starting point position shown in FIG. 7A. At this point thefive wafers 104 are removed all at once from the substrate alignmentapparatus 100 by the wafer transfer unit 256.

[0218] In the above description, we assumed a state in which the angularposition of the notches 104 a of the five wafers supported by thesubstrate support pins 107 was limited to a range of the angle θ=60°flanking the extension line AO of the line connecting the position B ofthe optical sensors 116 and the rotational center O. However, it is alsoconceivable that the notches 104 a will not be within the specifiedangle θ range, so this method must be universal enough that notchdetection is possible even when the notches 104 a are outside thespecified angle θ range. Furthermore, interference between the supportpoles 105 and the pick-up poles 110 occurs when the wafers 104 supportedon the support poles 105 are rotated in a state in which any wafer 104has been picked up by the pick-up poles 110, so limitations imposed bythis interference must also be considered.

[0219] This problem of interference between the support poles 105 andthe pick-up poles 110 will be described through reference to FIG. 10A.When the wafers 104 are finally placed on the pick-up poles 110, we wantthe notch positions of the various wafers 104 to arrive at the notchalignment position (optical sensor position) S. If the notch positionsof the wafers 104 on the support poles 105 at this point are not withinthe range of θ=60° as shown in FIG. 10A, the notches 104 a cannot bemoved to the notch alignment position S. This is because, there is alimited range of motion in the wafer peripheral direction in the notchalignment operation with this apparatus. In this notch alignmentoperation, the pick-up poles 110 must be moved from the retractedposition shown in FIG. 7B in the inward radial direction of the wafers,and set in a position that allows pick-up, as shown in FIG. 10A.Accordingly, the range over which the support poles 105 can move in thewafer peripheral direction is limited to the range in which there is nointerference between the support poles 105 and the pick-up poles 110. Inthis apparatus, plenty of room is left between the support poles 105 andthe pick-up poles 110, and the movable range is determined so as tocover at least the notch shifting (±30°) that occurs in the washingprocess.

[0220] An apparatus that solves the above problems and which is able toaccommodate notches 104 a outside the specified angle θ range will nowbe described. First, the region of this apparatus in which a search fornotches can be performed, and the region in which this search cannot beperformed will be described through reference to FIG. 10B. The wafers104 are supported by three support poles 105 disposed at approximateintervals of 180°, 90°, and 90°. When a search is conducted for thenotches 104 a of the wafers 104, the sensor pole 117 must be moved fromits retracted position in the inward radial direction of the wafers andset in a position that allows a search for notches, as shown in FIG.10B. Therefore, on the wafers 104 are formed three searchable regions R1to R3, which are bounded by the support poles 105 and in which a searchfor the notch position can be performed within a range such that thereis no interference between the sensor pole 117 and the support poles105, and three unsearchable regions D1 to D3, which are near the supportpoles 105 and in which a search for the notch position cannot beconducted because the range of motion is limited so that there will beno interference between the sensor pole 117 and the support poles 105.The ranges of the notch position searchable regions R1 to R3 are 148°,81°, and 81°, respectively. The ranges of the notch position searchableregions given here are just examples, and can be further widened bymodifying, for example, the width and shape of the support poles 105 andthe sensor pole 117, or the clearance between these poles in order toavoid interference between the poles.

[0221] The notch alignment method will now be briefly described. First,a search for a notch 104 a is conducted in the 148°, 81°, and 81°searchable regions R1 to R3 of the wafers 104. If no notch is found, itmeans the notches 104 a are somewhere in the unsearchable regions D1 toD3. In this case, all the wafers are temporarily picked up by the pickuppoles 110, just the support poles 105 are rotated by a specific angle,and the wafers 104 are returned onto the support poles 105. Thisoperation allows the notch positions to be shifted with respect tot hesupport poles 105, moving the notches 104 a from the unsearchableregions into one of the searchable regions R1 to R3. After this, thesearchable regions R1 to R3 are searched again. After the notches havebeen detected for all the wafers 104, the next step is to align thenotches 104 a at the specified location. First, a decision is made as towhether the notch positions are within the θ range. This decision ismade according to the angular position data for the notches 104 a thathas been detected and stored. If the notch positions are within the θrange, the wafers 104 are rotated so that the notches 104 a come to thenotch alignment position S, and are placed on the substrate support pins107. If the notches 104 a are outside the θ range, then they cannot bemoved to the notch alignment position S by a single rotation due tolimitations of the movable range, so the notch positions are shifted alittle at a time. Specifically, to shift the notch positions, the wafers104 are temporarily picked up, the support poles 105 are rotated by thespecified angle in the direction opposite to the direction in which thenotch positions are moved, the wafers 104 are returned to the supportpoles 105, and the support poles 105 are rotated by the specified angleso that the notch positions will approach the notch alignment positionS. This procedure is repeated until the notch positions enter the θrange, at which point the notches 104 a can be aligned to the notchalignment position S. Here, the notches 104 a are moved in the directionof the shortest path. Specifically, in FIG. 10(a), the notches 104 a aremoved clockwise if they are on the right side, and are movedcounterclockwise if on the left side. In this figure, the notches 104 aare on the left side, so they are moved counterclockwise. Theabove-mentioned shortest path is selected according to the storedangular position data.

[0222]FIG. 9 is a block diagram of the control component that controlsthe mechanisms for performing the above-mentioned notch alignment. Thecontrol component comprises a control circuit 150, drivers 151 and 152,and electromagnetic valves 153 and 154, and has the following functions.

[0223] The rotation of the motor 106 of the substrate support mechanismis controlled in order to rotate a plurality of substrates all at onceand detect the notches of the various substrates,

[0224] (a) the rotation of the motor 106 of the substrate supportmechanism is controlled in order to perform wafer alignment (notchalignment) one wafer at a time on the basis of the notch detectionvalues for the various wafers,

[0225] (b) an individual alignment completion signal is outputted whenthe alignment of a single wafer 104 is complete,

[0226] (c) the motor 112, slide mechanism 113, and air cylinders 115 ofthe substrate retraction mechanism are controlled in order tosuccessively retract the wafers 104 that have undergone alignment fromthe substrate support mechanism one at a time on the basis of theindividual alignment completion signals,

[0227] (d) the control of (a) to (c) is performed for the remainingwafers 104 after the retraction of the wafers 104 that have undergonealignment,

[0228] (e) an overall position completion signal is outputted whenalignment is completed for all the wafers,

[0229] (f) the rotation of the motor 106 of the substrate supportmechanism is control so that the substrate support mechanism will bereturned to its initial state prior to the notch detection, while allthe aligned substrates are still retracted by the substrate retractionmechanism, and

[0230] (g) the motor 112, slide mechanism 113, and air cylinders 115 ofthe substrate retraction mechanism are controlled in order to return tothe substrate support mechanism all of the plurality of aligned wafersthat had been retracted.

[0231] FIGS. 11 to 13 illustrate the details of the flow in the aboveseries of operations related to the above-mentioned control component.

[0232] Five wafers 104 are put all at once into the substrate alignmentapparatus 100 by the wafer transfer unit 256 and transferred onto thethree support poles 105 (step 201). After this transfer, the supportpoles 105 are rotated 180° up to the notch detection commencement pointfor notch detection, changing the state in FIG. 7A to the state in FIG.7B (step 202). The sensor pole 117 is moved forward until the opticalsensors 116 reach the positions where notches can be detected (step203). Everything up to this point is notch detection preparation.

[0233] The next step is performing notch detection for the searchableregions. Specifically, the notches 104 a are searched for all at oncefor the five wafers 104 with respect to the range with an angle of 148°(first region R1) between the support poles 105 (step 204). After notchdetection, the sensor pole 117 is retracted and the sensors 116 movedaway (step 205). The reason for this is to avoid interference with thesupport poles 105 during the transition to searching other regions, andto avoid interference with the wafers 104 when they are picked up.

[0234] At this point a decision is made as to whether the notches 104 aof all the wafers 104 have been detected (step 206). If they have, theflow moves on to step 213, and the substrate support pins 107 areinserted at the positions where pick-up is possible. If they have notall been detected, the flow moves to step 207, and notch detection isperformed for the next region of the wafer with an 810 angle (the secondregion R2). A decision is made as to whether the notches 104 a of allthe wafers 104 have been detected (step 208). If they have, the flowmoves on to the above-mentioned step 213. If they have not, the flowmoves to step 209, and notch detection is performed for the remainingregion of the wafer 104 with an angle of 81° (the third region R3).

[0235] A decision is made as to whether the notches of all the wafershave been detected (step 210). If they have, the flow moves on to theabove-mentioned step 213. If they have not, it is assumed that thenotches 104 a are in one of the above-mentioned three unsearchableregions D1 to D3, the flow moves to step 211, and the pick-up poles 110are inserted at the positions where pick-up is possible. The notchpositions are shifted with respect to the support poles so that thenotches 104 a that were in the unsearchable regions D1 to D3 will enterthe searchable regions R1 to R3 (step 212). After the notches 104 a thatwere in the unsearchable regions are thus moved into the searchableregions, the flow returns to step 203, and the above-mentioned series ofnotch detection operations (steps 203 to 210) are once again carried outfor the searchable regions. The above procedure allows the notches 104 aof all the wafers 104 to be detected.

[0236] Once the notch positions for all the wafers 104 have beendetected, the pick-up poles 110 are inserted into the positions wherepick-up is possible as mentioned above (step 213), and after this step213 is complete, the flow moves on to step 214 in order to carry outnotch alignment and pickup. At this point, a decision is made as towhether the notch position of the lowermost wafer 104 which has yet tobe picked up is within the θ (60°) range (step 214). This decision ismade using the stored notch angular position data. If the position iswithin the θ range, then the relative position of the notch 104 a withrespect to the support poles is shifted the required amount so that thenotch 104 a will enter a region within the θ range (step 218), and theflow returns to the above-mentioned step 214.

[0237] If the position is within the θ range, the support poles 105 arerotated such that the notch position of the lowermost wafer 104 whichhas yet to be picked up is at the notch position S that is ultimatelydesired (step 215). The wafer 104 that has undergone notch alignment isthen picked up (step 216). Next, a decision is made as to whether thereare any wafers 104 that have yet to be picked up (step 217). If thereare, the flow returns to the above-mentioned step 214, and steps 214 to217 are repeated until all of the wafers have been picked up.

[0238] Once all of the wafers have been picked up, the flow moves on tostep 219, at which point the support poles 105 are rotated such thatthey are in the notch detection commencement position (the state in FIG.7B) while the wafers 104 are still picked up by the pick-up poles 110.After this, the wafers 104 on the pick-up poles 110 are placed on thesupport poles 105 (step 220), and the pick-up poles 110 are retracted(step 221). The support poles 105 are then rotated to their startingpoint positions and returned to the positions shown in FIG. 7A (step222). Finally, the wafers are removed by the wafer transfer unit 256(step 223).

[0239] The individual processing steps 207, 209, 212, and 218 mentionedabove will now be described in detail through reference to FIGS.13A,13B,13C and 13D.

[0240] (a) Step 207 (Notch Detection in Second Region)

[0241] First the individual processing step 207 will be described indetail through reference to FIG. 13A. The support poles 105 are rotatedthe required amount so that the second region of the wafers 104 becomessearchable (step 2071). The optical sensors 116 are inserted (step2072), and a search is made for notches 104 a only for undetected waferswith respect to the 810 range of the wafers 104 between the supportpoles 105 (step 2073). After this search, the optical sensors 116 areretracted (step 2074).

[0242] (b) Step 209 (Notch Detection in Third Region)

[0243] Next the individual processing step 209 will be described indetail through reference to FIG. 13B. The support poles 105 are rotatedthe required amount so that the remaining third region of the wafers 104becomes searchable (step 2091). The optical sensors 116 are inserted(step 2092), and a search is made for notches 104 a only for undetectedwafers with respect to the 810 range of the wafers 104 between thesupport poles 105 (step 2093). After this search, the optical sensors116 are retracted (step 2094).

[0244] (c) Step 212 (Shifting the Positions of Notches in theUnsearchable Regions so that they Enter the Searchable Regions)

[0245] Next the individual processing step 212 will be described indetail through reference to FIG. 13C. The wafers 104 on the supportpoles 105 are picked up by the pick-up poles 110 (step 2121). Afterthis, the support poles 105 are rotated the required amount so that thenotches 104 a move from the unsearchable regions to the searchableregions (148°, 81°, and 81°). Here, for those wafers whose notches havebeen detected, the data is corrected such that the amount of rotationhere will be reflected in the detected notch position data. In specificterms, the amount of rotation is added to the detected notch positiondata (step 2122). The above-mentioned specific amount that the supportpoles 105 are rotated is at least (360°−(148°+81°+81°))/3=16.7°. Afterthis specific amount of rotation, the pick-up poles 110 are lowered andthe wafers 104 returned onto the support poles 105, and the pick-uppoles 110 are retracted (step 2123).

[0246] (d) Step 218 (Putting the Notches of the Wafers in a Regionwithin the θ Range)

[0247] At the end the individual processing step 218 will be describedin detail through reference to FIG. 13D. The lowermost wafer 104 on thesupport poles 105 which has yet to be picked up is picked up by thepick-up poles 110 and retracted (step 2181). The support poles 105 arerotated the required amount in the direction opposite to the directionin which the notches 104 a are moved (step 2182), the pick-up poles 110are lowered, and the wafers picked up in the previous step are returnedonto the support poles (step 2183). After this, the support poles 105are rotated so that the notches 104 a will go from the notch positionsto the notch alignment position in the direction of the shortest path(clockwise or counter-clockwise) (step 2184). As mentioned above, theshortest path is determined by the stored angular position data for thenotches 104 a. Specifically, in FIG. 10A, the notches 104 a are rotatedcounterclockwise if they are on the left side, and clockwise if on theright side. After this, the flow returns to step 214, and a decision ismade as to whether the notch position is within the θ range. If not,steps 2181 to 2184 are carried out again, and these steps are repeateduntil the notch position is within the θ range.

[0248] FIGS. 14A,14B,14C and 14D illustrate how the wafers 104 that haveundergone notch position detection in steps 214 to 218 are rotated therequired amount and the notch positions 104 a are aligned on the line OB(see FIGS. 7A and 7B). The dotted lines in the figures express therotational transition of the support poles 105, while the one-dot chainlines are lines passing through the wafer center and the notch 104 a,and express the rotational transition of the wafers 104. The reasonthese dotted lines and one-dot chain lines have been drawn on the wafers104 is to facilitate an understanding of the rotational transition ofthe wafers with respect to the support poles. When this operation isactually carried out, the pick-up poles 110 are inserted in the inwardradial direction of the wafers, but to make the operation easier tounderstand, the figures are drawn with the pick-up poles 110 in aretracted state.

[0249] After notch position detection of all the wafers 104, a decisionis made as to whether the notch position of the wafer 104 about toundergo notch alignment (the lowermost wafer 104 which has yet to bepicked up) is within the 0 range, using the stored angular positiondata. If the notch position is outside the θ range, a decision is madeas to whether it is on the left or right side of the line AB (see FIGS.7A and 7B), again using the stored angular position data. If it is onthe right side, the wafer 104 is rotated the required amountcounterclockwise, or clockwise if on the left side, and the shortestpath is taken in moving the notch 104 a onto the line OB.

[0250] In the initial state (after notch detection and before notchalignment), we will assume that the notch position of the wafer 104 isat the lower left (FIG. 14A). In this case, since the notch 104 a is notwithin the θ range and is to the left of the line AB, the wafer 104 isrotated clockwise by the required amount so that the notch 104 a will bemoved by the shortest path onto the line OB. The wafer 104 istemporarily picked up, and just the support poles 105 are rotated therequired amount counterclockwise, which is the direction opposite to thedirection in which the notch 104 a is moved. Therefore, the notchposition of the wafer 104 does not move with this operation (FIG. 14B).The wafers 104 are returned to the support poles 105, and the supportpoles 105 (that is, the wafers 104) are rotated clockwise by therequired amount. This moves the notch position clockwise by the requiredamount (FIG. 14C). The wafers 104 are once again picked up and thesupport poles 105 rotated by the required amount counter-clockwise,which is the direction opposite to the direction in which the notch 104a is moved (FIG. 14D). The wafers 104 are returned to the support poles105 and rotated clockwise. This moves the notch position further aroundto the right (FIG. 14E). Thus, the notch position is shifted to withinthe θ range and finally aligned on the line OB.

[0251] In the description up to this point, the wafers 104 were firsttemporarily picked up and just the support poles 105 were rotated by therequired amount in the direction opposite to the direction in which thenotches were shifted, but the support poles 105 may also be rotated inthe direction in which the notch positions will reach the line OB by theshortest path, with the wafers 104 resting on the support poles 105prior to the above operation.

[0252] In the first embodiment, the turntables used for wafer placementand required for each wafer are eliminated, and in their place thesupport poles 105 are provided for supporting the wafers, and pick-uppoles are provided so that notch-aligned wafers can be retracted, sonotch alignment can be performed for a plurality of wafers all at once.Also, if the substrate outer periphery 104 b is supported with thetapered portions 99 during notch alignment, the support will be in astate of linear or point contact, so the contact surface area will besmall, fewer particles will be generated than when the backs of thewafers are vacuum chucked, and furthermore, since it is the substrateouter periphery 104 b that is being supported, there will be a markedreduction in the clinging of particles to the backs of the wafers.

[0253] Even with the substrate alignment apparatus of the above firstembodiment, however, the operation is still fairly complicated andalignment is not very fast. Another problem is that the apparatus heightis increased by disposing the motor 106 and other such drive componentsunder the wafers 104. In view of this, the second embodiment describedbelow solves these problems by introducing an individual turntablesystem.

[0254] Second Embodiment (FIGS. 15 to 18)

[0255] This is a substrate alignment apparatus having five motorscorresponding to the number of wafers, and is capable of detecting thenotches of all five wafers with almost no contact with the wafers.

[0256] As shown in FIG. 15, the substrate alignment apparatus isequipped with a housing 300 having five shelves 301 to 305 (including atop plate 301) and a bottom plate 306, and has an open design in whichthe two front sides of the housing 300 are open. Turntables 307 with acommon rotational center are attached to the top sides of the fiveshelves 301 to 305, allowing the notches of the five wafers to bedetected. The turntables 307 are capable of independent rotary drive,and their drive mechanisms consist of timing belts 308 and motors 309.The motors 309 are provided to the side, rather than under theturntables 307. In addition to functioning as attachment plates for theturntables 307, the shelves 301 to 305 also function as barriers forpreventing any particles that might be generated from clinging to thesurface of the next lower wafer. The corner sections at the front of theshelves 301 to 305 are cut off, and serve as the loading and unloadingpoint for the wafers.

[0257] As to how the motors 309 are attached in the illustrated example,they are split up and disposed on the front and back sides of theshelves 301 to 305 or on the left and right of the housing 300, thereason being that the length of the motors 309 requires them to bedisposed so that they take up as little space as possible. The spacingbetween the turntables here is kept to within 30 mm.

[0258] Three support pins 310 are attached at approximately 120°intervals around the outer periphery of the top sides of the turntables307 such that the outer periphery of the wafers can be supported.Optical sensors 311 are attached at the backs of the shelves 301 to 305(the opposite side from where the wafers are loaded), allowing the notchof each of the five wafers supported on the support pins 310 to bedetected.

[0259]FIGS. 16A and 16B are side views illustrating the details of thedrive system of the turntables 307. FIG. 16A is an embodiment(corresponding to the uppermost level) in which the motor 309 isprovided to the side of the turntables 307, and FIG. 16B is acomparative diagram in which the motor 309 is provided directly beneaththe turntables 307. To facilitate comparison, FIG. 16B is turnedupside-down.

[0260] As shown in FIG. 16A, a pulley 313 is fitted to the rotary shaft314 of the turntable 307, a pulley 312 is fitted to the drive shaft 315of the motor 309, and a timing belt 308 is provided between the pulleys312 and 313. The timing belt 308 follows along the space between theturntable 307 and the shelf 301. If the motor 309 is provided to theside of the turntable 307, and the rotary shaft 314 and the drive shaft315 are arranged in parallel, then part of the height (thickness) of themotor 309 including the drive shaft 315 can be accommodated within thethickness of the turntable 307, and the apparatus height La can belowered and the apparatus made more compact because the drive shaft 315and the rotary shaft 314 do not need to be connected serially. Incontrast, if the motor 309 is below the turntable 307 as shown in FIG.16B, then the connection length of the drive shaft 315 of the motor 309and the rotary shaft 314 of the turntable 307, and the height of themotor 309 protrude fully as the height of these parts, making theapparatus height Lb taller and the apparatus bulkier.

[0261]FIG. 17 is a detail view of the above-mentioned optical sensors311 and support pins 310. The optical sensor 311 has a cross sectionwith a square indentation on the side, and the outer periphery 104 b ofthe wafer 104 fits into the opening 316 that is this indentation. Alight emitting element 311 a is provided above the indentation, and alight receiving element 311 b below, and the design is such that thereis a change in the amount of light received by the light receivingelement 311 b when the notch arrives at the opening 316, allowing thenotch position to be detected.

[0262] The diameter of the turntable 307 is slightly smaller than thediameter of the wafer 104 placed thereon, and the support pins 310protrude out from the outer periphery of the turntable 307 in theoutward radial direction so as to support the outer periphery 104 b ofthe wafer 104. Forming the support pins 310 that support the outerperiphery 104 b of the wafers 104 in this manner eliminates anyinterference between the support pins 310 and the optical sensors 311,so the wafers 104 can be rotated without restriction and notch alignmentcan be performed faster and more easily.

[0263] The support surfaces of the support pins 310 on which the wafers104 are supported have tapered portions 317, which allow the wafercenter to be aligned more easily with the center of rotation of theturntables 307, allowing any eccentricity of the wafers 104 to becorrected automatically. Also, supporting the substrate outer periphery104 b on the tapered portions 317 prevents particles from clinging tothe backs of the wafers.

[0264] As shown in the figure, the support pins 310 have an approximateL-shape, and are attached to the outer periphery of the turntable 307 ina position in which they are turned sideways with the bent section 318facing down. The depression of this L-shaped bent section 318 serves asa recess for the protruding light receiving element 311 b of the opticalsensor 311. Forming this recess allows the facing distance to beshortened between the light emitting element 311 a and the lightreceiving element 311 b, so the apparatus can be more compact.

[0265] The above-mentioned recess is not essential, however. If there isno sensor recess on the back side, then there should be no interferenceof the support pins 310 between the light emitting element 311 a and thelight receiving element 311 b of the optical sensor 311.

[0266] The procedure for aligning five wafers all at once with thesubstrate alignment apparatus having the above structure will now bedescribed through reference to FIG. 18.

[0267] Five wafers 104 are loaded into the substrate alignment apparatuswith a wafer transfer unit capable of handling five wafers at a time,and these wafers are transferred to the various turntables 307 (steps401 and 402). The various turntables 307 are independently rotated andthe notches are detected by the various sensors 311 (step 403), and thenotches are then aligned to the specified position (step 404). Oncenotch alignment has been completed for all five of the turntables 307,the wafers 104 are transferred out of the substrate alignment apparatusby the wafer transfer unit. In the above notch alignment, the wafers arerotated and the notches are detected on the first rotation, and arecontrolled such that they are decelerated at the point of detection,their rotation is stopped, and they are returned by the amount they havegone too far. At first glance this operation appears to result inalignment that is simultaneous with notch detection.

[0268] Thus, in the second embodiment, the outer periphery 104 b of thewafers 104 is supported by the tapered portions 317 of the support pins310 provided to the turntables 307, the wafers 104 are rotated, and thenotches 104 a of the wafers 104 are detected and arranged in non-contactfashion, and this affords a reduction in particle generation andeffectively prevents particles from clinging to the backs of the wafers.Also, the motors 309 that rotate the turntables 307 are provided forevery one of the turntables 307 and operate them independently, so evenif a notch position is badly shifted, its alignment will not be hinderedby the other wafers, and each notch can be dealt with independently.Also, the apparatus height can be lowered because the motors 309 are notdisposed directly beneath the wafers 104, and are instead provided tothe side of the turntables 307, with the drive force to the turntables307 being transmitted by timing belts 308. Thus, with a relativelysimple construction, there is no restriction on rotation, and sincealignment of the wafers is accomplished all at once, notch positiondetection is extremely fast.

[0269] Nevertheless, even with this second embodiment, the followingproblems are encountered when the notches overlap the support pins 310,or when the support pins 310 come to the tweezers entrance positionafter notch alignment. For example, as shown in FIGS. 19A and 19B, ifthe support pin 310 overlaps the notch position, the support pin 310will block the optical path of the optical sensor and prevent thedetection of the notch position. Also, as shown in FIGS. 20A and 20B,there are times when the positions of the support pins 310 are shiftedbecause the turntables 307 have been rotated for the sake of notchalignment, and the support pins 310 are in the way of the forwardmovement of the tweezers 257 of the wafer transfer unit 256. In a casesuch as this, the turntables 307 must be brought to their starting pointso that the tweezers 257 can move forward, but the problem with this isthat the notches that were so carefully aligned become misaligned again.

[0270] In view of this, in the third embodiment discussed below, in acase such as that described above, all of the wafers are picked up andretracted, and the turntables are rotated by a specific amount so as toshift the positions of the support pins, and this solves theabove-mentioned problems. This pick-up mechanism incorporates theconcept of the first embodiment.

[0271] Third Embodiment (FIGS. 21 to 29)

[0272] This is a substrate alignment apparatus with which notchalignment is possible even when the notches of the wafers overlap withthe support pins of the turntables.

[0273] The basic structure shown in FIG. 21 is the same as that of thesubstrate alignment apparatus in the second embodiment shown in FIG. 15.The difference is that the substrate retraction mechanism employed inthe first embodiment is provided for picking up and retracting thewafers, so that when a notch overlaps with a support pin, the wafer isfirst picked up and retracted, during which time just the turntable isshifted, and the wafer is put back on the shifted turntable, therebypreventing overlap with the support pins. Also, even if a support pinblocks the forward path of the tweezers after alignment, here again,just the turntable is shifted to open up the forward path of thetweezers.

[0274] Three pick-up poles 321 are elevatably provided around the outerperiphery of a stack of five turntables 307. The direction in whichthese poles are erected is parallel to the rotational axis of theturntables 307. Pick-up support pins 322 that support the substrateouter periphery of the wafers and pick up the wafers are provided at aspecific pitch in the lengthwise direction to these pick-up poles 321such that they project like arms toward the center of rotation of thepick-up support pins 322. In FIG. 21, the pick-up support pins 322 aredrawn such that they overlap with the support pins 310 provided to theturntables 307. The wafer support surfaces of the pick-up support pins322 are wafer-bearing edge surfaces that are slightly tapered, just asin the first embodiment.

[0275] The three pick-up poles 321 go all the way through the shelves301 to 305 and are integrally attached to a base 323 provided in thespace formed between the lowermost shelf 305 and the bottom plate 306.The base 323 can be raised and lowered by an air cylinder 324. Thepick-up poles 321 merely go up and down, and neither rotate nor moveback and forth. When the pick-up poles 321 are raised, the pick-upsupport pins 322 are stopped at the substrate outer periphery and pickup the wafers from the support pins 310. After being picked up, thewafers are returned to the support pins 310 by the lowering of thepick-up poles 321.

[0276] How the various motors 309 that rotate the turntables 307 areattached is the same as described in the second embodiment, but here wewill describe another way of laying out and attaching the motors. Thisis illustrated in detail in FIG. 22A. The motor 309 cannot be disposedon the arrow side of line Z because the motor 309 will interfere withthe wafer 104 during loading. As shown in FIG. 22B, the spacing betweenthe shelves 301 to 305, that is, the spacing between the variousturntables 307, must be no more than 30 mm due to restriction of thepitch varying mechanism of the wafer transfer unit 256. If an attempt ismade to align the shaft of an upper motor 309 (motor (2) at the secondlevel) with that of a lower motor 309 (motor (4) at the fourth level),the motors will interfere with each other and the spacing cannot be keptwithin 30 mm, so the motors are alternately shifted in their positionswith respect to one another (FIG. 22A). The reason the motors 309 are atthe corners is to provide enough distance to accommodate the timingbelts 308 between the motor shafts and the center of the turntables 307.Similarly, the purpose of staggering the motors 309 to the left andright at odd and even numbered levels is to keep the motors frominterfering with one another, so as to provide a spacing of no more than30 mm between levels.

[0277]FIGS. 23A and 23B is a detail view of the substrate alignmentapparatus shown in FIG. 21, with FIG. 23A being a plan view and FIG. 23Ba vertical cross section of the lowermost level. The support pinposition sensor 325 shown in FIG. 23A is used to return the turntable307 to its starting point. The turntable 307 is returned to its startingpoint using the signals from this sensor, which prevents interferencebetween the tweezers and the support pins 310 on the turntable 307, aswill be discussed below. As shown in FIG. 23B, the air cylinder 324raises and lowers the pick-up poles 321 by driving the base 323, and aguide 327 is provided parallel to elevator rods 326 of the air cylinder324. This guide 327 allows the pick-up poles 321 to be raised andlowered more smoothly.

[0278] As shown in FIG. 24, the pick-up poles 321 in the thirdembodiment has the pick-up support pins 322 provided at equidistantspacing in the lengthwise direction, and when the wafers 104 are pickedup, all five of them are picked up at once. Just as in the firstembodiment, the wafer support surfaces of the pick-up support pins 322are wafer-bearing surfaces that are slightly tapered, and the wafers aresupported around their outer periphery.

[0279] Notch alignment with the above structure will now be describedthrough reference to FIGS. 25A,25B to 28, including a case when a notchposition cannot be detected because the notch of a wafer overlaps asupport pin 310.

[0280] As shown in FIG. 27, five wafers 104 are loaded into thesubstrate alignment apparatus by a wafer transfer unit capable ofhandling five wafers all at once, and are transferred to the variousturntables 307 (steps 501 and 502). After this transfer, the turntables307 are rotated and the notches 104 a are detected (step 503). Afterthis notch detection, those wafers 104 whose notches 104 a have beendetected are aligned so that their notches are parallel (step 504). Inthis embodiment, just as in the second embodiment, the turntables 307are decelerated at the point when notches 104 a are detected, rotationis stopped, and the wafers are returned by the amount they have gone toofar. Therefore, for wafers 104 whose notches 104 a have been detected,at first glance this operation appears to result in alignment of thenotches 104 a simultaneously with detection of the notches 104 a. Afterthis, a decision is made as to whether the notches 104 a of all thewafers 104 have been detected (step 505). If the notches 104 a of allthe wafers 104 have been detected, then the notch alignment is completefor all the wafers 104 at that point, and the flow jumps to step 509. Ifthe notches 104 a of all the wafers 104 have not been detected, thismeans that there is a notch 104 a overlapping a support pin 310 of theturntable 307, so an operation is performed to eliminate thisoverlapping for that wafer 104. First, the pick-up poles 321 are raisedby the operation of the air cylinder 324, and all the wafers 104supported by the support pins 310 of the turntables 307 (FIG. 25A) aretemporarily picked up and retracted by the pick-up poles 321 (FIG. 25B)(step 506).

[0281] While all the wafers 104 are retracted, the support pins 310 ofthe turntable 307 of the wafer 104 whose notch 104 a was not detectedare rotated by a specific amount and the turntable 307 is halted (step507). As shown in FIG. 26, when the turntable is stopped, the supportpins 310 and the pick-up support pins 322 are stopped at a positionshifted by the angle δ. Therefore, any overlap between a support pin 310and a notch can be eliminated. In this state, the air cylinder 324 isoperated in reverse to lower the pick-up poles 321 (step 508), and thewafers 104 are transferred to the support pins 310 (FIG. 25A). Thisallows the notch positions to be detected.

[0282] Once the overlap between the support pins 310 and the notches 104a has been eliminated so that the notches 104 a can be detected, theflow returns to step 503, and the above-mentioned series of notchdetection and notch alignment operations are performed again for thosewafers 104 whose notches 104 a have not been detected (steps 503 to505). The above operation allows notch alignment to be performed for allthe wafers 104.

[0283] After the notch alignment of all the wafers, all the wafers 104are retracted (step 509), and the turntables 307 are rotated by therequired amount during this retraction so as to return all theturntables to their starting point (step 510). This return to thestarting point is performed after every notch alignment, regardless ofwhether support pins are in the tweezers transfer position, in order tocreate a state in which the next notch alignment can be performed. Afterthis, the wafers are returned onto the turntables 307 (step 511). Thewafers 104 are then smoothly removed using the wafer transfer unit (step512).

[0284] As discussed above, the notches of the wafers 104 taken out of aFOUP by the wafer transfer unit can be aligned in their specifiedpositions by a substrate alignment apparatus having a substrateretraction mechanism, even when the notches are placed overlapping withthe support pins of the substrate alignment apparatus. Also, even if thesupport pin positions of the turntables are in the forward path of thetweezers after completion of notch alignment for all the wafers, thewafers are all temporarily lifted by the pick-up mechanism, during whichtime the turntables, which are not carrying anything, are rotated by aspecific amount and returned to their starting point. After this, thewafer lifting mechanism is lowered and the wafers are put back on theturntables that have undergone starting point alignment, so the forwardmotion of the tweezers is not impeded.

[0285] In the third embodiment, when a notch overlaps a substratesupport pin and the notch cannot be detected, this overlap is eliminatedusing a substrate retraction mechanism, but as shown in FIG. 29, theoverlapping notch can be detected without the use of a substrateretraction mechanism if the support pin 330 is molded from a materialthat is transparent with respect to the light of the optical sensor.Even though the notch 104 a overlaps with the support pin 330, thesupport pin 330 does not block the light because it is transparent,allowing the notch 104 a to be detected. Quartz glass is good as thematerial of the support pins 330. An advantage to making the supportpins 330 from a transparent material is that the notches 104 a can bedetected even when the notches 104 a are overlapping the support pins330, eliminating the need for the notch detection to be carried outagain, and this shortens the time it takes for notch detection. Hereagain, however, a substrate retraction mechanism is necessary because ofthe problem of interference between the support pins 330 on theturntables 307 and the transfer unit tweezers that move forward into thesubstrate alignment apparatus.

[0286] As a rule, the above first embodiment is premised on the notchposition being within a specific angle θ range, but the second and thirdembodiments do not have this restriction, and notches can be detectedwherever they are. The flow of the control components in the second andthird embodiments was described, but no control block diagram is given.The control blocks would be structured basically the same as in thefirst embodiment (see FIG. 9).

[0287] In the first embodiment, the notch positions are detected, andthe notches are successively aligned to their specific positions, one ata time, on the basis of angular position data for the detected notches,and the notch alignment time here is 36 seconds for five wafers (7.2seconds/wafer). The results are even better in the second and. thirdembodiments, in which the notches are aligned to their specificpositions all at once on the basis of angular position data for thedetected notches, taking 19 seconds for five wafers (3.8 seconds/wafer).The above time for the third embodiment is for when there is no overlapbetween notches and support pins, or is the shortest time when a notch104 a overlaps a support pin 330 and the support pins 330 are made of atransparent material. When the material is not transparent and there isoverlap between a notch and support pin, the time is 30+α seconds forfive wafers (6+α′/wafer). The above notch alignment times are justexamples of when the present apparatus is used, and shorter times can beachieved by varying the rotational speed, the pick-up speed, and othersuch factors to the extent that no problems such as wafer shiftingoccur.

[0288] From the standpoint of wafer support stability, it is preferablefor there to be three support poles and three pick-up poles, but four ormore may also be used. In these embodiments, a substrate transfer unitis used for loading and unloading the wafers to and from the substratealignment apparatus, but when the pitch between wafers in the substratealignment apparatus is different from the pitch between wafers in theFOUP or boat, then the pitch between the tweezers of the substratetransfer unit must be changed to match this.

EXAMPLES

[0289] The structure of a specific substrate alignment apparatus of thefirst embodiment, and the pitch values P1 and P2 when notches aredetected on all five wafers at once will now be described.

[0290] (1) Substrate Alignment Apparatus

[0291]FIG. 31 is an oblique view of a specific substrate alignmentapparatus of the first embodiment.

[0292] The substrate alignment apparatus has a two-level structure. Thefirst level is a mechanism chamber 601 containing mechanisms forraising, lowering, advancing, and retracting pick-up poles 610, and thesecond level is an alignment mechanism chamber 602 where notch alignmentis performed.

[0293] The alignment mechanism chamber 602 at the second level comprisesa turntable 603 rotatably provided over the mechanism chamber 601, threesupport poles 605 that are erected around the outer periphery of theturntable 603 and that support five horizontally stacked wafers, atriangular plate 609 that is supported at the top of the three supportpoles 605 and that covers the surface of the five wafers supported onthe support poles 605, a sensor pole 617 that is provided such that itcan move back and forth in the radial direction of the turntable 603,that has five optical sensors 618 for notch detection, and that detectsthe notches in the wafers with these optical sensors 618, and a motor606 for driving the turntable.

[0294] The mechanism chamber 601 at the first level is equipped with ahousing 600 having a top plate 611 and bottom plate 619 with a modifiedpentagonal shape produced by cutting off one corner of a square. Thefront two sides of the housing 600 are open. The inside of this openhousing 600 is provided with an approximately disk-shaped horizontalplate 613 that is provided elevatably, three pick-up poles 610 that areretracted within the mechanism chamber 601 in their initial state andrise during notch alignment to a position where pick-up is possible onthe second level, three cylinders 615 that move the various pick-uppoles 610 back and forth in the radial direction, a ball screw 616 thatgoes through the horizontal plate 613, a ball nut (not shown) attachedto the horizontal plate 613 and threaded onto the ball screw 616, and amotor 612 that rotates the ball screw 616.

[0295] The reason the pick-up poles 610 are retracted in the mechanismchamber 601 at the first level in the initial state is to prevent themfrom interfering with the wafers during the loading of the wafers if thepick-up poles 610 are in the position at the second level where pick-upis possible. Specifically, as shown in FIG. 32, the pick-up poles 610have to be retracted because they are within the operating range inwhich the wafers are transferred during wafer transfer. This is why theabove-mentioned retraction of the pick-up poles 610 is necessary, andwafer transfer is always conducted in the retracted position.

[0296] When the motor 612 is driven, the ball screw 616 rotates and thehorizontal plate 613 rises along the ball screw 616. As the horizontalplate 613 rises, the pick-up poles 610 rise up from their retractedposition at the first level and rise all the way to the position at thefirst level where pick-up is possible. The cylinders 615 attached to thehorizontal plate 613 are actuated to move the pick-up poles 610 in theinward radial direction, and the pick-up support pins slide under theouter periphery of the wafers 104. The motor 612 is driven again, and asthe pick-up poles 610 rise, the wafers 104 supported on the supportpoles 605 are lifted up and transferred to the pick-up poles 610.

[0297] The change points in the flow of FIGS. 11 and 12 when notchalignment is performed using the substrate alignment apparatus with theabove structure are the point in step 202 when the support poles 605have been rotated to the notch detection commencement position and thepick-up poles 610 are then further raised to the position where pick-upis possible, and the point in step 221 when the pick-up poles 610 havebeen retracted and are then further lowered out of the way down to themechanism chamber 601 at the first level. As long as the operation ofraising the pick-up poles 610 to a position where pick-up is possible isafter step 201 but before step 211, it may be performed at any time.

[0298] (2) Pitch P1 and P2

[0299] When the wafers 104 are actually picked up one by one, the waferbending ε, the spacing between the wafers 104 and the pick-up supportpins 111 and between the wafers 104 and the substrate support pins 107,and so forth must be taken into account in order to avoid interferencebetween the wafers 104 and the pick-up support pins 111 and substratesupport pins 107. An example will now be given of a method in whichthese factors are considered, for determining the pitch P1 of thepick-up support pins 111 and the pitch P2 of the substrate support pins107 in the actual picking up of the wafers 104 one by one.

[0300] In FIGS. 8A,8B,8C and 8D, S1, S2, . . . , S5 are the pickupsupport pins 111 (in order from the bottom), K1, K2, K5 are thesubstrate support pins 107 (in order from the bottom), W1, W2, . . . ,W5, are the wafers 104 (in order from the bottom), s is the thickness ofthe pick-up support pins 111, k is the thickness of the substratesupport pins 107, w is the thickness of the wafers 104, and ε is thewafer bending.

[0301] Also, in FIGS. 8A,8B,8C and 8D, if we let

[0302] (1) the spacing between the lowermost pick-up support pin S1 andthe lowermost wafer W1 in the initial state (FIG. 8A),

[0303] (2) the spacing between the substrate support pin Km and thepicked-up water Wm in a state in which the m-th wafer (m is an integerfrom 1 to 4) has been picked up, and the spacing between the waferW(m+1) that is picked up next and the pick-up support pin S(m+1) thatpicks up this wafer (m=1 in FIG. 8B), and

[0304] (3) the spacing between the uppermost wafer W5 and the uppermostsubstrate support pin K5 in a state in which the last (fifth) wafer hasbeen picked up, and the spacing between the lowermost wafer W1 and thesecond lowest substrate support pin K2 (FIG. 8D)

[0305] each be ΔL, then the following equations hold true.

P2=P1+2ΔL  (4)

4P1=3P2+k+w+2ΔL  (5)

[0306] The spacing ΔL here must be at least greater than the waferbending ε so that there will be no interference between the wafers 104and the substrate support pins 107 and pick-up support pins 111 (FIG.33). An even better margin ΔL′ is provided to obtain ΔL=ε+ΔL′.Considering that ε=0.3 mm and the margin ΔL′≧1 mm, the value duringdesign was set to ΔL=2 mm.

[0307] Based on FIGS. 8A,8B,8C and 8D, the pick-up pitch is 2ΔL=4 mm.Also, s=k=2 mm and w=0.775 mm, and if we let w=0.775 mm be approximately1 mm, then Formulas 4 and 5 become as follows.

P2=P1+4

4P1=3P2+7

[0308] Thus, the pitch P1 of the pick-up support pins 111 of the pick-uppoles 110 and the pitch P2 of the substrate support pins 107 of thesupport poles 105 are determined at P1=19 mm and P2=23 mm.

[0309] The values given here for the margin ΔL′, the thickness s of thepick-up support pins 111, and the thickness k of the substrate supportpins 107 are merely examples, and the thickness w of the wafers 104 canbe varied according to the type of wafer, the material, the size, andother such factors. Thus, the pitch P1 of the pick-up support pins 111of the pick-up poles 110 and the pitch P2 of the substrate support pins107 of the support poles 105 can be set to various values.

[0310] What the spacing ΔL from the wafer should be set to in the designof a notch alignment apparatus is not entirely clear in terms of therelationship of bending in a 12-inch wafer. In view of this, the spacingat which there is no interference when the substrate support poles arerotated when the wafers are picked up is tentatively assumed to be 2 mm.This is because the presence of bending is believed to be irrelevant ifthe spacing is at least six times the bending of 0.3 mm.

[0311] Also, the discussion here was about constant spacing of thepick-up support pins 111 and constant spacing of the substrate supportpins 107, but the spacing does not have to be equidistant as long as thewafers after notch alignment can be successively picked up one at atime.

[0312] With the present invention, the substrates are supported by theirouter periphery, rather than their back sides, so particles do not clingto the backs of the substrates. Also, a plurality of substrates can bealigned all at once by providing support poles capable of supporting aplurality of substrates. A plurality of substrates can also be alignedsimultaneously by providing a plurality of levels of turntables carryingthe substrates. Furthermore, throughput can be increased by utilizingthe idle time of the substrate transfer unit to perform the alignment ofthe substrates. In particular, by providing a substrate retractionmechanism, even if problems such as overlap between an orientation flator notch and a substrate support component should occur, this problemcan be eliminated and the orientation flat or notch of the substratealigned to its specific position.

What is claimed is:
 1. A semiconductor manufacturing method, including astep of detecting the position of the orientation flat or notch of asubstrate and aligning it to a specific position, wherein a substratetransfer unit that transfers substrates to a processing chamber orprocessing jig is used for the orientation flat or notch alignment ofsaid substrates.
 2. The semiconductor manufacturing method according toclaim 1, wherein the orientation flat or notch alignment of thesubstrates is performed in a transfer chamber in which said substratetransfer unit is installed.
 3. The semiconductor manufacturing methodaccording to claim 1, wherein the substrates are removed from asubstrate carrier by said substrate transfer unit and put into asubstrate alignment apparatus that performs the orientation flat ornotch alignment of the substrates, and the substrates are taken out ofsaid substrate alignment apparatus by said substrate transfer unit afterthe orientation flat or notch alignment of the substrates andtransferred to the processing chamber or processing jig.
 4. Thesemiconductor manufacturing method according to claim 1, wherein theorientation flat or notch alignment of the substrates is performed aheadof time by exchanging substrate carriers and repeating the followingsteps (a) to (d): (a) the substrates are removed from the substratecarrier by said substrate transfer unit and put into a substratealignment apparatus that performs the orientation flat or notchalignment of the substrates, and orientation flat or notch alignment ofthe substrates is performed; (b) the substrates that have undergoneorientation flat or notch alignment are taken out of said substratealignment apparatus and returned to said substrate carrier by saidsubstrate transfer unit; (c) repeating the above steps (a) and (b) untilthe orientation flat or notch alignment is finished for all of thesubstrates in said substrate carrier; and (d) the substrate carrier forwhich the orientation flat or notch alignment of the substrates has beenfinished is stored on a storage shelf.
 5. The semiconductormanufacturing method according to claim 4, including a step in which, ifthe orientation flat or notch alignment of the substrates in thesubstrate carrier has been performed ahead of time, this information isstored, a judgment as to whether the substrates to be transferred havealready undergone orientation flat or notch alignment is made on thebasis of this information when the substrates are transferred, and ifthe substrates to be transferred have already undergone orientation flator notch alignment, then the substrates are taken out of the substratecarrier by said substrate transfer unit and transferred directly to theprocessing chamber or processing jig without first going through saidsubstrate alignment apparatus.
 6. A semiconductor manufacturing methodincluding a step of detecting the position of the orientation flat ornotch of a substrate and aligning it to a specific position, whereinsaid orientation flat or notch alignment of each substrate is performedby placing the substrate horizontally and rotating it while the outerperiphery of the substrate is supported by a substrate supportcomponent.
 7. The semiconductor manufacturing method according to claim6, including a step in which said substrate is temporarily retractedfrom said substrate support component so that the relative positions ofsaid substrate and said substrate support component in the peripheraldirection are shifted, and then the retracted substrate is once againsupported by said substrate support component.
 8. The semiconductormanufacturing method according to claim 7, wherein, in the shifting ofthe relative positions of said substrate and said substrate supportcomponent in the peripheral direction, the position of said substratesupport component is corrected so that the orientation flat or notch ofthe substrate will not overlap with the substrate support component, orso that the substrate support component will not block the forward pathof the substrate transfer unit component as the substrate is taken outof said substrate support component by the substrate transfer unit. 9.The semiconductor manufacturing method according to claim 8, wherein, ifthere is overlap between said substrate support component and saidorientation flat or notch of the substrate while the substrate outerperiphery is supported by the substrate support component, the substrateis temporarily retracted from said substrate so that the relativepositions of the substrate and the substrate support component in theperipheral direction are shifted, and then said substrate is once againsupported by the substrate support component, thereby avoiding saidoverlap.
 10. The semiconductor manufacturing method according to claim8, wherein said substrate is temporarily retracted from said substratesupport component after said orientation flat or notch alignment of thesubstrate, and said substrate support component is set in a toleranceposition that doesn't block the forward path of the substrate transferunit, after which said substrate is once again supported by thesubstrate support component.
 11. A semiconductor manufacturing methodincluding a step of detecting the position of the orientation flat ornotch of a substrate and aligning to a specific position, wherein, inthe orientation flat or notch alignment of a plurality of substrates,the plurality of substrates are stacked and supported by a substratesupport mechanism and rotated all together by the required angle,whereby the orientation flats or notches of all of the substrates aredetected by a detection sensor, and the detection information is stored,the substrate support mechanism is rotated on the basis of saiddetection information so as to perform orientation flat or notchalignment for one substrate at a time, each substrate that has undergoneorientation flat or notch alignment is retracted from the substratesupport mechanism one by one while the position of said each substratein the peripheral direction is maintained, and after the orientationflat or notch alignment and retraction are finished for all of thesubstrates, the retracted substrates are returned to the substratesupport mechanism.
 12. The semiconductor manufacturing method accordingto claim 11, including a step of rotating the plurality of substratesall at once by a specified angle when the orientation flat or notchposition of the plurality of substrates cannot be detected because theorientation flat or notch position is too far away from the place wherethe detection sensor is installed, so that said orientation flat ornotch position is brought closer to said place where the detectionsensor is installed and the orientation flat or notch position can bedetected, through this rotation by said specified angle.
 13. Thesemiconductor manufacturing method according to claim 11, wherein, whenthe orientation flats or notches of the substrates cannot be detectedeven when the substrate support mechanism is rotated by the requiredangle, the following steps (a) to (d) are performed so as to alloworientation flat or notch detection: (a) the substrates are retractedfrom the substrate support mechanism; (b) the substrate supportmechanism is rotated by a specified angle; (c) the substrates arereturned to the substrate support mechanism; and (d) the substratesupport mechanism is rotated by the required angle and the orientationflat or notch position is detected.
 14. The semiconductor manufacturingmethod according to claim 11, wherein, in the alignment of theorientation flats or notches of the substrates to a specific positionafter completion of the orientation flat or notch position detectionoperation for all of the substrates, if the orientation flat or notch ofthe substrate cannot be aligned to the specific position with a singlerotation because the orientation flat or notch position is too far awayfrom the specific position, the following steps are repeatedly performeduntil the orientation flat or notche of the substrate is aligned withthe specified position: (a) the substrate support mechanism is rotatedthe required amount in the direction that is the shortest path from theorientation flat or notch position to the specified position; (b) thesubstrates are retracted from the substrate support mechanism; (c) thesubstrate support mechanism is rotated the required amount in theopposite direction from that in (a); and (d) the substrates are returnedto the substrate support mechanism.
 15. The semiconductor manufacturingmethod according to any of claim 8, wherein orientation flat or notchalignment is performed all at once for a plurality of substrates.